Splenic Flexure Research Articles

Colonic stenting in acute malignant large bowel obstruction: audit of efficacy and safety in a Singapore tertiary referral centre.

Acute malignant large bowel obstruction (MBO) occurs in 8%-15% of colorectal cancer patients. Self-expandable metal stents (SEMS) have progressed from a palliative modality to use as bridge to surgery (BTS). We aimed to assess the safety and efficacy of SEMS for MBO in our institution. The data of patients undergoing SEMS insertion for MBO were reviewed. Technical success was defined as successful SEMS deployment across tumour without complications. Clinical success was defined as colonic decompression without requiring further surgical intervention. Rates of complications, median time to surgery, types of surgery and rates of recurrence were studied. Seventy-nine patients underwent emergent SEMS placement from September 2013 to February 2020. Their mean age was 68.8 ± 13.8 years and 43 (54%) patients were male. Mean tumour length was 4.2 cm ± 2.2 cm; 89.9% of malignant strictures were located distal to the splenic flexure. Technical and clinical success was 94.9% and 98.7%, respectively. Perforation occurred in 5.1% of patients, with none having stent migration or bleeding. Fifty (63.3%) patients underwent SEMS insertion as BTS. Median time to surgery was 20 (range 6-57) days. Most (82%) patients underwent minimally invasive surgery. Primary anastomosis rate was 98%. Thirty-nine patients had follow-up beyond 1-year posttreatment (median 34 months). Local recurrence and distant metastasis were observed in 4 (10.3%) and 5 (12.8%) patients, respectively. Insertion of SEMS for acute MBO has high success rates and a good safety profile. Most patients in this audit underwent minimally invasive surgery and primary anastomosis after successful BTS.

Clinical features of colorectal duplication in children: A study of 25 cases

PurposeTo describe the clinical features and surgical management of pediatric colorectal duplication. MethodsTwenty-five patients with colorectal duplication at Beijing Children's Hospital between January 2010 and December 2020 were reviewed. Colorectal duplications were divided into cystic, diverticular, tubular and mixed types according to shape. ResultsOf the patients, 64% were female, and 44% had accompanying malformations. Abnormal prenatal ultrasound findings (24%), abnormalities immediately found after birth (28%), and postnatal subjective symptoms (48%) were the main clinical presentations. Cystic lesions were observed in 16 patients (64%), including 12 in the colon and 4 in the rectum. Diverticular lesions were observed in 4 patients (16%), and all originated from the sigmoid colon. Among the 4 patients (16%) with tubular lesions, 3 involved the total colon, and the other originated from the splenic flexure to the proximal sigmoid colon. The patient with mixed duplication presented an intact enteric cyst within tubular duplication of the total colon. The mean age at surgery was 20 (0.3–130) months. Except for 4 total colon duplications, complete surgical resection of duplication lesions was performed in all patients. The “distal cross-section, mucosa stripping, and closure” procedure was performed in 3 patients with total colon duplication. Eighteen patients (72%) were followed up for a median time of 54.5 (5–129) months and recovered uneventfully. ConclusionsOwing to various clinical presentations, colorectal duplication requires careful preoperative differential diagnosis. Complete surgical resection is the preferred radical method for treating cystic, diverticular and short tubular colorectal duplications, except for total colon duplications. Level of EvidenceLevel IV.

S1841 Colorectal Squamous Cell Carcinoma: An Usual Presentation of an Unusual Cancer

Introduction: Squamous cell carcinoma (SCC) is an extremely rare cause of colorectal malignancy and makes up to 0.025% of all colorectal malignancies. Clinically, it presents with similar signs and symptoms as colorectal adenocarcinoma. Due to the rarity of this pathology, there is limited information on optimal treatment and disease prognosis, making early identification with a diagnostic colonoscopy and biopsies essential. Here, we present a rare case of colorectal SCC in the hepatic flexure with local invasion to the gallbladder and liver in a patient with chronic abdominal discomfort. Case description/methods: A 54-year-old female with hypertension and diabetes mellitus presented to the clinic complaining of abdominal discomfort for one year. She denied hematochezia, melena, hematemesis, weight loss, and changes to her bowel habits. Abdominal examination demonstrated epigastric and right upper quadrant tenderness. Initial routine laboratory studies were unremarkable. Ultrasound of the abdomen showed a right hepatic lesion which was confirmed on follow up CT scan of the abdomen that demonstrated a 7.1 × 6.7 × 7.6 cm heterogeneous mass in the transverse colon, inseparable from the gallbladder and left hepatic lobe. A subsequent MRI of the abdomen demonstrated consistent findings. Analysis of tumor markers demonstrated elevated carcinoembryonic antigen at 69.4 ng/mL (reference range: ≤5.0 ng/mL). Whereas, alpha-fetoprotein and cancer antigen 19-9 were negative. The patient also tested negative for Hepatitis C, HIV, and HPV and was found to be non-immune to Hepatitis B. Considering a high suspicion for malignancy, a diagnostic colonoscopy was performed which revealed a 5 cm polypoid, partially circumferential, non-obstructing erythematous mass at the hepatic flexure (Figure 1). Immunohistochemical stains of the biopsies including CK7, P40, and KI-67 (50-60%) were found to be positive. The pathology of the hepatic flexure mass was consistent with squamous cell carcinoma. She successfully underwent surgical resection of the malignancy followed by chemotherapy treatment. Discussion: In conclusion, patients with colorectal SCC is extremely rare, but presents later in the disease process with a worse prognosis. Practicing clinicians should be aware of less common causes of colorectal malignancy as early identification with a diagnostic colonoscopy is essential. Due to the rarity of the case, extensive evaluation is needed to confirm the absence of primary disease anywhere else in the body.Figure 1.: Colonoscopy revealing a 5 cm polypoid mass at the hepatic flexure.

S1917 Complicated Diverticulitis of the Sigmoid Flexure in a Patient with Left Nephrolithiasis

Introduction: Complicated diverticulitis is defined as diverticular inflammation associated with hemorrhage, abscess, phlegmon, perforation or obstruction. There are currently no reported cases of complicated diverticulitis occurring secondary to obstructive nephrolithiasis. We report a patient admitted for a left ureteral stone, whose significant perinephric inflammation was suspected to play a role in the development of complicated diverticulitis. Case description/methods: A 76 year old woman with history of recurrent nephrolithiasis presented with acute left flank pain. On arrival, she was mildly tachycardic. Physical exam was notable for left costovertebral angle tenderness. Labs were notable for an elevated blood urea nitrogen of 25 mg/dL. Computed tomography (CT) abdomen showed a 6 mm obstructing calculus within the left proximal ureter causing moderate hydronephrosis and significant peri-nephric inflammation. The patient was started on ceftriaxone. The next day, she had a worsening leukocytosis and an acute kidney injury, so she was taken urgently for left ureteral stent placement. Postoperatively, she had significant abdominal pain, so a repeat CT abdomen was obtained. It revealed inflamed diverticulum at the splenic flexure with an associated abscess abutting the spleen, consistent with complicated diverticulitis. She was managed supportively with nasogastric tube decompression, pain control, and broadened antibiotics. On hospital day 8, her abdominal pain worsened. Repeat CT abdomen showed enlargement of the perisplenic abscess and multiple new small abscesses anterior to the spleen. The patient was taken for laparoscopic splenectomy, which was complicated by iatrogenic perforation of the stomach, peritonitis, and septic shock. After a prolonged and complicated hospital stay in the surgical intensive care unit, the patient was discharged to a long term care facility. Discussion: Our patient's complicated diverticulitis was suspected to be secondary to her left ureteral stone. While most cases of diverticulitis occur at the sigmoid colon, our patient’s was at the splenic flexure, in close proximity to the left renal fossa where significant inflammation was noted on initial imaging. It is also possible that her diverticulitis was a consequence of iatrogenic ureteral injury during cystoscopy. Clinicians should be aware that complicated diverticulitis may occur in relation to nephrolithiasis.Figure 1.: a: Synaptophysin positive tumor cells b: Chromogranin A positive tumor cells c: Colonoscopy showing 2 cm mass at Hepatic flexure. d: High grade adenocarcinoma arising in a background of sessile serrated adenoma e: CK7 positive immunohistochemical staining.

S1911 Primary Colon Burkitt’s Lymphoma Presenting as Colonic Obstruction

Introduction: Primary colon lymphomas are very rare colon malignancies and Burkitt´s lymphoma (BL) variant is usually diagnosed in children and immunocompromised patients. BL is a highly aggressive malignancy and is the fastest growing human cancer. Primary colon BL (PCBL) is very rare in adults with few reported cases located around ileocecal valve region. There are only two published cases of PCBL causing colonic obstruction due to ileocecal valve region involvement. We present a unique PCBL case located in splenic flexure of colon causing colonic obstruction. Case description/methods: A 56-year-old female presented with 10-day history of worsening diffuse abdominal pain, nausea, vomiting & inability to pass gas. She had diffuse abdominal tenderness & hyperactive bowel sounds. Labs were unremarkable. Abdominal CT scan revealed complete colonic obstruction from splenic flexure exophytic colonic mass measuring 14 x 10 x 10 cm with small mesenteric & hepatic lesions. Emergent laparoscopic transverse colon diverting loop colostomy performed due to high tumor burden that appeared to be unresectable. Subsequent colonoscopy showed large obstructing colon mass at splenic flexure of colon & proximal colon segments were dilated with decompressed distal colon. Biopsies from colon mass were indicative for diffuse large B-cell lymphoma with extensive necrosis, high proliferation index, Ki-67 80% positive. Ultrasound guided liver biopsy revealed high grade B-cell lymphoma. FISH analysis revealed findings of MYC/IGH fusion in approximately 100% of nuclei without rearrangement of BCL2 or BCL6, consistent with PCBL. Chemotherapy initiated (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, rituximab) with an excellent response. Surveillance colonoscopy at 5-year post-treatment showed no concerns for disease recurrence. Discussion: PCBL is not only very rare in adults but also rare outside of ileocecal area, where concentration of lymphoid tissue is relatively increased. In english literature there are only 2 published cases of PCBL at ileocecal valve location causing colonic obstruction. To the best of our knowledge, our PCBL case is unique as being the first case of PCBL atypically located in distal colon & causing colonic obstruction. Older age or atypical GI locations cannot exclude the possibility of PCBL & should be considered as part of differential diagnosis for high-grade GI lymphomas. With advances in chemotherapy, PCBL may respond well to therapy even in disseminated stage with colonic obstruction.Figure 1.: A: Nuclear medicine PET CT scan showing multiple FDG avid mesenteric masses consistent with lymphoma and evidence of hepatic metastasis. Figure B: CT scan abdomen revealing large splenic flexure exophytic colonic mass causing colonic obstruction. Figure C: Large obstructing colon mass seen at the splenic flexure of colon during colonoscopy. Figure D: Colon mass biopsy with hematoxylin & eosin stain at 200x magnification showing extensive necrosis with crush artifact and rare clusters of viable large neoplastic cells.

S1734 A Rare Case of Non-Small Cell Lung Carcinoma With Metastasis to the Colon: A Case Report

Introduction: Squamous Cell Carcinoma (SCC) when found in the Lung is classified as Non-Small Cell Lung Carcinoma (NSCLC). It has a high potential to metastasize most commonly to the brain, liver, or bone. We present a rare case of metastasis of NSCLC to the colon leading to constipation. Case Description/Methods: This is a case of a 58-year-old male with a history of NSCLC with known metastasis to the subcutaneous abdomen, liver and spleen. The patient was on maintenance therapy with nab-paclitaxel and underwent a Computer Topography (CT) Chest and Abdomen to evaluate for disease progression. The CT revealed a circumferential mass at the hepatic flexure (Figure 1a & 1b) suspicious for a colonic neoplasm. In the Gastroenterology clinic he endorsed right upper quadrant abdominal pain and worsening constipation but denied weight loss, overt bleeding or change in stool caliber. He underwent a colonoscopy which revealed an ulcerated, partially-obstructing circumferential mass at the hepatic flexure (Figure 2a). The mass was biopsied and tattooed for localization (Figure 2b). The pathology revealed metastatic NSCLC. Surgery was consulted and the patient was scheduled for a right hemicolectomy with end ileostomy and mucus fistula. Discussion: Primary colonic SCC is a rare entity making up less than 1% of colon carcinomas, while 95% are adenocarcinomas. NSCLC with metastasis to the colon is also considered rare with few cases reported in the literature and accounts for 0.5% of lung cancer cases. NSCLC most commonly metastasizes to the brain, liver or bone. This happens when NSCLC invades local lymph nodes and can then enter the lymphatic system eventually spreading hematologically. SCC usually arises from a mutation of the p53 gene, by inhibiting apoptosis of abnormal cells. This then progresses into a lesion and can eventually spread to metastatic disease by seeding to other parts of the body. When it happens in the colon, the presentation is similar to all colorectal cancers; rectal bleeding, abdominal pain, change in bowel habits, change in stool caliber, and weight loss. In our patient a CT scan to monitor for progression discovered a lesion in the colon. Colonoscopy was performed to differentiate between primary and metastatic disease. To date no guidelines on the management of cases like this exist, however surgical resection with chemotherapy is considered the best management. This case illustrates that while rare a metastatic SCC should be in the differential when evaluating patients with colonic lesions.Figure 1.: Figure 1a & b: CT abdomen revealed a circumferential mass at the hepatic flexure of the colon.Figure 2.: a & b: Colonoscopy showed a mass that was biopsied and tattooed for localization.

S1752 Medullary Carcinoma of the Colon Presenting as Sepsis in a Patient With Ulcerative Colitis and Primary Sclerosing Cholangitis

Introduction: Medullary carcinoma (MC) of the colon is a rare histological subtype of poorly differentiated adenocarcinoma representing approximately 5-8 cases of every 10,000 colon cancers diagnosed. The prevalence of inflammatory bowel disease in patients with primary sclerosing cholangitis (PSC) ranges upwards of 50%, and the combination of both ulcerative colitis (UC) and PSC leads to a fourfold increase of colorectal cancer. Here we present a case of medullary colon cancer presenting as bilateral deep vein thrombosis (DVT) and sepsis, and to date there have been no reports of primary colonic MC in a patient with PSC. Case Description/Methods: A 30-year-old African American man with a history of UC on mesalamine and PSC on ursodiol presented with anemia and hematochezia. It was thought that he was having an UC flare and was treated with steroids. Colonoscopy showed multiple anal and rectal ulcers. Shortly after, he was diagnosed with bilateral lower extremity DVT, requiring placement of an IVC filter. He then developed sepsis, at which point he was diagnosed with E. coli bacteremia. CT scan showed a right lower quadrant necrotic and exophytic mass with surrounding adenopathy concerning for malignancy (Figure 1). Laboratory results demonstrated leukocytosis of 25.5, microcytic anemia with hemoglobin 7.6 g/dl and MCV 67.2 fl, thrombocytosis of 513 x 103/µL, elevated alkaline phosphatase of 574 U/L with total bilirubin of 1.9 mg/dL of which direct bilirubin was 1.3 mg/dL. SGOT 39 U/L, SGPT 58 U/L, GGTP 360 U/L. Carcinoembryonic Antigen (CEA) was elevated to 3.3 ng/mL. Colonoscopy demonstrated a large friable mass located in the ascending colon that appeared malignant and spanned approximately 4 cm (Figure 2). After undergoing a right hemicolectomy, pathology demonstrated poorly differentiated colonic MC with invasion through the muscularis propria (T3), with metastatic carcinoma identified in 8 of 43 lymph nodes (N2b). Discussion: Colonic MC tumors tend to be located proximally, rarely present with metastasis, and have been strongly associated with hereditary nonpolyposis colorectal cancer. It is twice more common in females and the mean age at diagnosis is 69.3±12.5 years. It is extremely rare in African Americans. These tumors can be difficult to distinguish from poorly differentiated adenocarcinomas and neuroendocrine tumors, but presence of positive calretinin staining in MC confirms diagnosis. This is the first report of MC of the colon in an individual with PSC, and one of the few in patients with UC.Figure 1.: A. CT abdomen/pelvis without contrast demonstrating a diffusely dilated, air-filled gastrointestinal tract extending from the stomach through the rectosigmoid colon. No transition point or obstruction noted. B. CT abdomen/pelvis with rectal contrast demonstrating an interposition of the hepatic flexure of the colon posterior and medial to the right lobe of the liver. No evidence of obstruction or strangulation noted. C. Endoscopy demonstrating a twisted, almost volvulus-like appearance at the splenic flexure, though without clear transition points.

COLORECTAL CARCINOMA: A CASE OF MALIGNANT FISTULA FORMATION PRESENTING AS SEPTIC SHOCK

TOPIC: Critical Care TYPE: Medical Student/Resident Case Reports INTRODUCTION: Colorectal carcinoma (CRC) is the third most common cause of malignancy in the United States. Common signs and symptoms include hematochezia, melena, abdominal pain, anemia, and change in bowel habits. Rarely, CRC can present with fistula formation and subsequent infection. Here we highlight a patient with known CRC who presented with intrapulmonary abscesses due to colopleural fistula formation. CASE PRESENTATION: A 57-year-old male with recently diagnosed stage IV colon adenocarcinoma presents with a productive cough of brown, foul-smelling sputum and left-sided chest and abdominal pain for three weeks. Vitals showed tachycardia and hypotension. Exam revealed diminished breath sounds of the left hemithorax and tenderness to palpation of the left chest wall and left upper quadrant. Labs were significant for anemia 6.2 g/dL, leukocytosis 21.3 thou/cmm with bandemia 17%, and peak lactate 20.1 mmol/L. Computed tomography (CT) of the chest, abdomen, and pelvis showed a large gas containing mass within the left lower lobe contiguous with the splenic flexure and chest wall as well as left-side intrapulmonary abscesses and extensive soft tissue gas within the left hemithorax concerning for pleurocutaneous fistula. These findings were consistent with colopleural fistula formation due to extension of his known splenic flexure mass. Patient was fluid resuscitated, transfused one unit of packed red blood cells, and started on vasopressors and broad-spectrum antibiotics. Multidisciplinary discussions determined that patient would require extensive surgical debridement for source control; however, his overall prognosis remained poor given the advanced state of his cancer and poor performance status. A goals of care discussion was held with the patient who declined surgery and opted to pursue hospice care. DISCUSSION: Colopleural fistula formation is an extremely rare complication of CRC with the potential to manifest as serious pulmonary infections arising due to perforation or invasion of nearby tissue. Our patient developed intrapulmonary abscesses and pleurocutaneous fistula with soft tissue gas concerning for necrotizing fasciitis due to colopleural fistula formation. Management involves a multidisciplinary approach and ultimately, requires emergent surgical intervention. Unfortunately, this is not always possible as in our patient who was too far advanced in his disease course making him a poor surgical candidate. CONCLUSIONS: Malignant fistulas associated with CRC can present as life-threatening infections, which require emergent surgical and medical management. It is important for all patients to undergo age-appropriate CRC screening with close follow-up to prevent such dire complications. REFERENCE #1: Lian R, Zhang G, Zhang G. Empyema caused by a colopleural fistula: A case report. Medicine (Baltimore). 2017 Sep;96(39):e8165. doi: 10.1097/MD.0000000000008165. PMID: 28953667; PMCID: PMC5626310. REFERENCE #2: Papagiannopoulos K, Gialvalis D, Dodo I, Darby MJ. Empyema resulting from a true colopleural fistula complicating a perforated sigmoid diverticulum. Ann Thorac Surg. 2004 Jan;77(1):324-6. doi: 10.1016/s0003-4975(03)01378-x. PMID: 14726092. REFERENCE #3: Siegel RL, Miller KD, Fuchs HE, Jemal A. Cancer Statistics, 2021. CA Cancer J Clin. 2021 Jan;71(1):7-33. doi: 10.3322/caac.21654. Epub 2021 Jan 12. PMID: 33433946. DISCLOSURES: No relevant relationships by Arjan Ahluwalia, source=Web Response No relevant relationships by Henry Lam, source=Web Response No relevant relationships by Kaitlyn Musco, source=Web Response No relevant relationships by Andres Zirlinger, source=Web Response

S1853 Gastrointestinal AL Amyloidosis: A Rare Cause of Symptomatic Colitis

Introduction: Gastrointestinal (GI) symptoms of systemic diseases are often poorly characterized. Evaluation of intractable symptoms may include advanced studies, such as computed tomography (CT) and magnetic resonance imaging scans, esophagogastroduodenoscopy (EGD) and colonoscopy. Amyloidosis, characterized by the extracellular deposition of insoluble misfolded proteins, can result in the deposition of abnormal proteins into the GI tract. GI amyloidosis (GIA) is difficult to diagnose and treat due to its variable etiologies and clinical manifestations. Current literature on GIA is vastly limited to case reports. We describe a case of GIA diagnosed by colonic biopsy. Case description/methods: 77-year-old female with past medical history of hypertension and chronic kidney disease presented with nausea, vomiting, diarrhea, left lower quadrant pain (LLQ) , anorexia, and a 20-pound weight loss. She was evaluated five months prior and treated for dyspepsia without relief. A recent CT scan of her abdomen revealed transverse, descending, and sigmoidal colonic wall thickening consistent with colitis. Antibiotics failed to improve her symptoms and unfortunately resulted in Clostridium difficile colitis. On physical exam, she was hypotensive, tachycardic, tender to palpation in the LLQ, and had 1+ pitting pedal edema. Labs revealed a leukocytosis, and anemia with hemoglobin 9.4 g/dL. GI pathogen panel was negative. Repeat CT scan revealed a thickened gastric wall in addition to previously noted colonic wall thickening. EGD and flexible sigmoidoscopy noted gastritis, duodenitis, and diffusely friable exudative colonic mucosa with underlying fibrosis (Figure 1). Pathology revealed extensive amyloid deposition. Bone marrow biopsy with flow cytometry showed plasma cell myeloma, confirming the diagnosis of GIA. Discussion: GIA is differentiated by systemic versus localized forms; the incidence of AL amyloidosis is approximately 1/100,000 in Western countries. Studies have shown that biopsy proven GIA is a rare phenomenon, consisting of as little as 3.3% of all cases. The most common symptoms of GIA are GI bleeding, malabsorption, nausea, vomiting, and protein-loss gastroenteropathies. Clinicians should be aware of these symptoms in elderly patients so that GIA can be diagnosed and treated early to minimize morbidity and mortality.Figure 1.: Endoscopic images demonstrating diffusely friable, exudative mucosa at the splenic flexure (A), descending colon (B,C) and sigmoid colon (D,E,F).

S2439 A Crohn's Disease Flare Masquerading as COVID-19 Infection

Introduction: The clinical presentation of an inflammatory bowel disease (IBD) flare can mimic COVID-19 infection. Gastrointestinal manifestations have been reported in over one half of COVID-19 patients, sometimes without associated respiratory symptoms. We report a patient whose Crohn’s Disease (CD) flare was challenging to diagnose due to concomitant COVID-19 infection. Case description/methods: A 26-year-old man with history of ileocolonic CD, on ustekinumab, presented with 1 day of diffuse abdominal pain, nausea, intractable vomiting, and chills. On arrival, he was mildly tachycardic. Physical exam was notable for mild abdominal tenderness. Erythrocyte sedimentation rate (ESR) was 54 mm/hr from a prior of 22 mm/hr and c-reactive protein (CRP) was 1.1 mg/dL from normal limits prior. COVID-19 testing was positive. Computed tomography (CT) abdomen was significant for mild edema of the terminal ileum and entire colon. Gastroenterology was consulted for concern of a CD flare. His clinical presentation was suspected to be from COVID-19 infection as opposed to CD because nausea, vomiting and chills were his predominant symptoms, as opposed to abdominal pain. Additionally, his CT findings were felt to be improved from his prior studies. ESR and CRP were noted to be unreliable markers to diagnose a CD flare in his situation because they could be elevated due to COVID-19 infection. The patient was managed supportively with as needed oxycodone for pain. On hospital day 2, the patient reported worsening abdominal pain and had a bloody bowel movement. A repeat CT abdomen now showed progressive colitis involving the entire colon and terminal ileitis, consistent with a CD flare. The patient was started on 40 mg daily prednisone with improvement in his symptoms. He was discharged on hospital day 4. Discussion: GI symptoms are commonly reported in patients with COVID-19. In a study of 318 adult patients hospitalized with COVID-19, 61% had at least one GI symptom. In particular, anorexia was reported in 35%, diarrhea in 34%, and nausea in 26%. Another study reported diarrhea in about 50% of COVID-19 patients. Given the nonspecific nature of these symptoms, and that they can present in the absence of respiratory complaints, clinicians should be aware that an IBD flare can masquerade as COVID-19 infection.Figure 1.: Initial CT abdomen, showing mild edema and hyperemia of the terminal ileum and ascending/transverse/proximal descending colon with skip lesions at the splenic flexure, consistent with clinical suspicion of a Crohn's flare.

S1881 Colonic Intussusception From a Necrotic Giant Lipoma

Introduction: Lipomas are the most common benign subepithelial lesions (SEL) of the colon. They usually originate in the submucosa, however, could rarely be found within muscularis propria or subserosa. Although usually asymptomatic, lipomas can become symptomatic depending on their size and/or location. Herein we present a case of colonic intussusception secondary to a necrotic giant lipoma. Case description/methods: Patient is a 58 year old woman with past medical history of uncontrolled hypertension resulting in two cerebrovascular accidents without residual deficits (currently on clopidogrel) and uncontrolled insulin dependent diabetes type 2 with nephropathy resulting in stage 5 chronic kidney disease leading to iron deficiency anemia (IDA) who presented to ambulatory surgery unit for colonoscopy for further evaluation of IDA. Colonoscopy revealed a 5 cm nearly obstructing ulcerated and necrotic SEL in distal transverse colon. Procedure was complicated by transient desaturation and patient underwent post-procedural computerized tomography (CT) scan to rule aspiration pneumonia as patient was found to have a pieces of ginseng root within the oral cavity. CT scan revealed a 4.8 cm predominantly fatty mass-like lesion at splenic flexure with edematous fat and mild circumferential thickening of wall of proximal descending colon possibly suggesting colocolic intussusception without evidence of bowel obstruction. The patient was admitted to surgical service and taken to the operating room for laparoscopic left hemicolectomy. Pathology revealed a partially necrotic submucosal lipoma with acute inflammation, fat necrosis, ulceration and granulation tissue. Discussion: Colonic lipoma leading to intussusception is a rare complication of otherwise benign SEL. They are typically asymptomatic but can present with obstruction, bleeding, intussusception, and/or abdominal pain. CT scan is the preferred imaging modality for diagnosing aforementioned complications. The differential diagnosis for incidental lesions identified on imaging includes malignancy, large pedunculated polyps or liposarcomas. Management for symptomatic colonic lipomas can be either endoscopic or surgical. Size, location and presenting symptoms are the determining factors for deciding on type of management. Endoscopic ligation (“Loop-And-Let-Go”) technique was contemplated, however, due to finding of intussusception and the fact that patient had to resume clopidogrel, a decision was made to proceed with surgical resection.Figure 1.: A. Image from CT scan revealing a mass in the colon B. Imaging from colonoscopy depicting large lesion nearly obstructing with intussusception C. Microscopic Appearance: Necrotic mucosa and fat globules with foamy macrophages consistent with necrotic lipoma.

S2418 Crohn’s Colitis Mimicking Ischemic Colitis: A Case Report

Introduction: Crohn’s disease (CD) can mimic ischemic colitis (IC) in the elderly. Here we present an elderly male diagnosed with CD when IC was initially suspected, and further evaluation revealed that CD was the primary diagnosis. Case description/methods: A 69-year-old male with a history of coronary artery disease with recent percutaneous coronary angioplasty & stent placement on aspirin and clopidogrel presented with hematochezia. He had an acute onset of a large amount of rectal bleeding and denied any other symptoms or having prior hematochezia or chronic diarrhea. Exam noted for hemodynamic stability with no tenderness to palpation of abdomen. Hemoglobin was 10.3 from 17 (Normal [N]: 13.5-17.5 gm/dl). Clinically suspected to have IC. Esophagogastroduodenoscopy (EGD) showed a small superficial non-bleeding gastric ulcer, gastritis, and duodenitis, and no stigmata of recent bleeding. Colonoscopy revealed three large deep ulcers in the proximal descending colon, splenic flexure, and distal transverse colon, with the largest ulcer measuring 50 mm. These ulcers were characterized by heaped up margins with some reactive granulation tissue, suggestive of chronicity. Biopsies showed focal acute cryptitis and diffuse lymphoplasmacytic inflammation in lamina propria without architectural distortion. CT angiography abdomen and pelvis showed widely patent arterial vasculature. Clopidogrel was held for 2 weeks to check healing of ulceration. Repeat colonoscopy showed similar findings, without improvement of ulcerations. Repeat colonic biopsies showed chronic moderately active colitis with ulceration, cytomegalovirus staining was negative. Fecal calprotectin was >3000 [N: < 49 ug/g]. C-reactive protein was 63 [N: < 9 mg/L]. MR Enterography with no small bowel disease but noted hyperenhancement and thickening in the ascending and transverse colon. The initial findings, work up and lack of resolution, was most consistent with CD. Discussion: It is critical to distinguish IC from CD for appropriate management of patients. Differentiating between IC and CD can be challenging in the elderly. Endoscopy and histologic evaluation can aid correct diagnosis. Repeat endoscopy to assess progression or resolution is of utmost importance in differentiating CD from IC, but data is limited on appropriate timing. Lack of follow up endoscopy will most likely lead to misdiagnosis and incorrect management of the underlying pathology. Thus, a high index of suspicion must be maintained when discerning CD from IC.Figure 1.: A: Initial colonoscopy showing heaping upped margins of the splenic flexure ulcerations. B: Repeat colonoscopy showing deep colonic ulceration with heaped up margins at the area of splenic flexure without any resolution.

S282 Association Between Colorectal Cancer (CRC) and Disease Stage in Patients Undergoing Screening Versus Diagnostic Procedures in a Public Hospital in New York City

Introduction: Effective screening programs have reduced CRC incidence by up to 70% in specific populations. However, participation rates are low especially among disadvantaged populations. We compared demographics, disease characteristics, and clinical stages of CRC patients referred for screening (S) or diagnostic (D) procedures. Methods: We constructed a de-identified database of CRC patients seen between January 1, 2016, and June 1, 2021. Patients who were symptomatic and underwent a diagnostic procedure (D), and patients who were referred for screening colonoscopy (S) were compared. Demographic and clinical data were extracted from the electronic health record. Variables of interest included age, sex, race, BMI, cigarette smoking, diabetes, continuity (seen > once in a primary care setting (Family Medicine, Internal Medicine, ObGyn) within 5 years of being diagnosed with CRC) vs non-continuity patients, right vs left colon (separated at splenic flexure), and non-advanced (Stages 0-2) vs advanced (Stages 3-4). Fisher exact test was used to compare stage, sex, presence of symptoms, and lesion location between the two groups. Two tailed t test was used to compare BMI and age. Results: 292 patients were included, 69.2% were (D) while 27.3% were (S). Of the 292 patients, 54.4% was found to have advanced CRC and 42.4% non-advanced. Mean age was 62, there were 55% women and 45% men, and around 75% percent were African American or Hispanic. Mean BMI was 27.8, 35% were diabetic, and 54.4% had a history of cigarette smoking. Around 80% of patients had signs or symptoms at diagnosis. There was a significant difference in disease stage between D and S; 83% of D had advanced CRC at diagnosis versus 17 % in S, (p< 0.001). A greater proportion of D patients had a history of smoking (p< 0.005). Differences in sex, age, BMI, and location between D and S were not statistically significant. Conclusion: In this retrospective study of CRC screening in two public hospitals, advanced CRC was more common in symptomatic patients. We also found that more than 2/3 of our continuity patients with CRC presented with symptoms compared to >90% of non-continuity CRC patients (data reported separately). Separate approaches are needed to increase the uptake of screening of CRC and to increase the amount of people that establish a primary care follow-up, in this disadvantag population.

S1737 Goblet Cell Adenocarcinoma: A Rare and Aggressive Appendiceal Neoplasm

Introduction: Goblet cell adenocarcinoma (GCA) is a rare and unique appendiceal neoplasm, containing features of both adenocarcinoma and neuroendocrine tumors (NETs). Also termed "goblet cell carcinoids" and previously considered a low-grade malignancy, these tumors are now known to be much more aggressive than traditional carcinoid tumors due to coexistence of high grade adenocarcinoma. In fact, up to 40% of cases present after development of distant metastasis, most commonly to the peritoneum. This has led to pressure for updated nomenclature removing the term "carcinoid" to prevent confusion and potential for incorrect management. Case Description/Methods: A 69-year-old Filipino male with minimal past medical history presented with a four day history of sharp, bloating-type abdominal pain and difficulty passing gas. He denied any other symptoms, specifically nausea, vomiting, constipation or diarrhea. Screening colonoscopy performed 3 years prior with intubation of the terminal ileum was normal. CT of the abdomen/pelvis demonstrated a small bowel obstruction due to a mass, appearing to arise from the terminal ileum, encompassing the cecum and appendix. Colonoscopy was requested, however after discussion with colorectal surgery service, the decision was made to proceed directly to surgical resection, given likelihood of malignancy. Pathology revealed goblet cell adenocarcinoma with peritoneal metastasis, consistent with stage 4B (T4b N2 M1b). Discussion: Goblet cell adenocarcinomas are more aggressive and have a worse prognosis than NETs. Therefore, they must be staged and treated as appendiceal carcinomas. The mixed histology of these tumors, has led to misdiagnosis and poor outcomes. Given the rapid spread of these tumors, a recent normal screening colonoscopy should not preclude prompt investigation of abdominal symptoms in at-risk patients, to include cross-sectional imaging, because surgical resection remains the primary curative treatment strategy. Furthermore, if suspected, preoperative colonoscopy for biopsy should not delay surgical resection. Current debate exists regarding extent of surgical resection required for Stage 1-2 GCAs. Additional treatment strategies for Stage 3-4 GCAs include 5-fluorouracil based adjuvant chemotherapy and hyperthermic intraperitoneal chemotherapy (HIPEC). The low five-year survival, 57% for Stage 3 and 19% for Stage 4, emphasize the importance of early diagnosis and treatment.Figure 1.: A. CT abdomen/pelvis without contrast demonstrating a diffusely dilated, air-filled gastrointestinal tract extending from the stomach through the rectosigmoid colon. No transition point or obstruction noted. B. CT abdomen/pelvis with rectal contrast demonstrating an interposition of the hepatic flexure of the colon posterior and medial to the right lobe of the liver. No evidence of obstruction or strangulation noted. C. Endoscopy demonstrating a twisted, almost volvulus-like appearance at the splenic flexure, though without clear transition points.

S1951 Candida albicans Enterocolitis in an Immunocompromised Host

Introduction: Neutropenic enterocolitis is a rare infection that occurs in immunocompromised patients. Although most cases are from bacterial pathogens, fungal etiologies have been recognized as a rare cause and are associated with a high mortality (up to 80%). Due to its rarity, there is a paucity of literature describing treatment regimens and their outcomes. We present a case of a patient with acute lymphoblastic leukemia (ALL) undergoing chemotherapy who developed neutropenic enterocolitis secondary to Candida albicans that was responsive to treatment. Case description/methods: A 35-year-old female with a past medical history significant for ALL complicated by recurrent CNS lymphoma presented to the ED for worsening acute on chronic pain. Though CBC on admission showed WBC within normal limits, she developed severe neutropenia with concurrent appearance of blasts. A bone marrow biopsy confirmed relapse of her ALL. On hospital day 8, she was noted to have multiple bloody bowel movements, abdominal pain, and hypotension. CTAP demonstrated inflammation in the cecum and ascending colon suggestive of neutropenic colitis. Colonoscopy demonstrated multiple superficial ulcers up to 1 cm in diameter in the cecum and multiple diffuse aphthae in the hepatic flexure and ascending colon (Figures 1a and 1b). Biopsies were notable for abundant yeast and hyphal forms infiltrating the necrotic mucosa as well as hyphae invading the wall of the venule consistent with an angioinvasive fungal infection (Figures 1c and 1d). The patient was started on micafungin and Amphotericin B, then transitioned to Posaconazole when PCR detected Candida albicans DNA. The patient’s hematochezia and abdominal pain resolved, and she was discharged home on prophylactic Posaconazole. She passed away 2.5 months later due to progression of her ALL. Discussion: When colonoscopy demonstrates broad based ulcers in immunocompromised patients with neutropenia and lower GI bleeding, there should be suspicion for fungal etiologies and initiation of broad-spectrum antifungals should be considered as delays in treatment are associated with increased mortality and morbidity. There is a lack of standardized guidance for treatment of fungal neutropenic enterocolitis, however, initiating treatment with broad spectrum antifungals and narrowing coverage after a species is isolated may represent an effective treatment strategy. Still, it is important to realize that mortality remains high even if patients recover from the initial fungal infection.Figure 1.: Sister Mary Joseph Nodule on CT Abdomen/Pelvis.

S1934 Acute Colonic Ischemia: A Rare Complication of Stevens-Johnson Syndrome

Introduction: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening mucocutaneous reactions characterized by necrotic epidermal detachment and blister formation. Mucosal involvement of oropharyngeal, ocular, and urogenital surfaces is most common, but involvement of the small bowel and colon is distinctively rare. We present a unique case of SJS with colonic involvement resulting in acute colonic ischemia. Case description/methods: A 36 year-old female with systemic lupus erythematosus, hypertension, and asthma presented with one day of fever and emesis after taking ibuprofen for sore throat. On admission, she was febrile to 104°F. Laboratory evaluation was non-diagnostic. A diffuse pink morbilliform rash was noted, which rapidly progressed to widespread erythema, targetoid lesions, and bullae. Skin biopsy was consistent with SJS. A week into hospitalization, she developed respiratory failure requiring intubation and transfer to the intensive care unit. CT of the chest, abdomen, and pelvis revealed multifocal pneumonia but normal small and large bowel. She was treated with broad spectrum antibiotics and one dose of subcutaneous etanercept. The patient then developed worsening abdominal pain and distension. Repeat abdominal CT showed marked diffuse colonic distension with pneumatosis from the cecum to proximal transverse colon (Fig. 1). Abdominal arterial vasculature was patent. Exploratory laparotomy confirmed full thickness colonic ischemia. She underwent right and transverse colectomy with end ileostomy. Histology of the colonic mucosa was consistent with ischemia. She was started on IVIG and IV methylprednisolone therapy. The patient gradually improved. Her recovery was complicated by intra-abdominal and pelvic abscesses requiring percutaneous drainage, along with persistent abdominal pain. Further evaluation of her pain included a normal ileoscopy and upper endoscopy and an abdominal CT demonstrating enteritis which was managed with supportive care. The patient was ultimately discharged to a rehabilitation facility. Discussion: SJS/TEN is a potentially fatal and often drug-induced dermatologic reaction involving mucocutaneous membranes. We present a case of SJS thought secondary to ibuprofen use resulting in acute colonic ischemia, which is infrequently encountered and associated with significant morbidity. Clinicians must maintain high suspicion for gastrointestinal involvement of SJS/TEN to allow for prompt diagnosis and intervention.Figure 1.: Colonoscopy revealing a 5 cm polypoid mass at the hepatic flexure.

S175 Water Exchange Increased Advanced Adenoma Detection in the Ascending and Proximal Colon As Compared to Air Insufflation

Introduction: Randomized control trials (RCT) showed significant increase in adenoma detection rate (ADR) with water exchange (WE) compared with usual air or CO2 insufflation colonoscopy. Advanced adenoma detection rate (AADR) is a validated surrogate marker for colorectal cancer risk (GI Endosc Clin N Am 2002;12:1). There was limited data of the impact of WE on AADR, probably due to the small sample sizes of RCT. Pooled analysis of 6 published RCT suggested that WE significantly increased overall ADR and overall AADR of the entire colon (JCG 2020;54:212). The impact of WE on ADR and AADR in the ascending colon, where interval cancers tend to cluster (AJG 2014;109:1375), is unknown. We test the hypothesis that WE increased AADR by aggregating the data of 4 RCTs conducted by our group in Chiayi and Hualien, Taiwan. Methods: Data from 4 RCTs (NCT01894191, NCT02737514, NCT01535326, and NCT01699399) comparing WE and air insufflation were aggregated. The demographic characteristics, procedure related outcomes, ADR and AADR were tabulated. Results: Both the WE and air insufflation group included 503 patients. Table 1 shows that the demographic characteristics were similar between the two groups. WE had significantly shorter withdrawal time [mean (SD), 13.0 (6.8) vs 12.6 (8.5), P=0.017], and higher Boston Bowel Preparation Scale scores than the air insufflation group. The ratio of aspirate water volume to infused water volume at cecum (107%) indicated proper implementation of WE (Table 1). The WE group had significantly higher overall ADR (46.4% vs 54.9%, P=0.008), with the difference mainly occurring in the ascending colon (23.0% vs 30.9%, P=0.005) than the air insufflation group. The WE group had significantly higher AADR in the ascending (4.6% vs 7.8%, P=0.048) and proximal (6.4% vs 10.5%, P=0.023) colon. The overall AADR (16.3% vs 19.7%) was numerically higher in the WE group (P=0.189, possibly a type II error) (Table 1). Conclusion: Interval cancers tend to occur in the right and proximal colon. The beneficial effect for WE to increase right and proximal colon AADR (a validated surrogate marker for colorectal cancer risk) might hold the potential to reduce the occurrence of interval cancers. The aggregated data of 4 RCTs showed WE had significantly higher AADR in the right colon and proximal colon as compared to air insufflation. Future studies to evaluate the impact of WE on the occurrence of interval cancers are justified.Table 1.: †Chi-square test; ††Fisher’s exact test; *Mann-Whitney test; ADR, adenoma detection rate; AADR, advanced adenoma detection rate; BBPS, Boston Bowel Preparation Scale. Advanced adenoma was defined as an adenoma with a diameter of ≥ 10 mm, significant villous features (> 25%), or high-grade dysplasia. The ascending colon included the cecum, ascending colon and hepatic flexure. The proximal colon included the cecum, ascending and transverse colon.

S1862 Endometriosis Presenting as a Mass at the Hepatic Flexure

S1862 Endometriosis Presenting as a Mass at the Hepatic Flexure

S1851 Chilaiditi Syndrome: A Case Report

Introduction: Chilaiditi’s sign was first defined over one hundred years ago by Demetrius Chilaiditi. Chilaiditi sign has a 0.025% to 0.28% incidence worldwide with a male to female ratio of 4:1. The bowel segments most commonly found interposed between the liver and diaphragm are the colonic hepatic flexure and transverse colon, however interposition of the small bowel can also occur. The following criteria must be met to diagnose Chilaiditi sign based on radiological findings: the right hemidiaphragm must be elevated above the liver by the intestine, the bowel must be distended by air to illustrate pseudo-pneumoperitoneum, and the superior margin of the liver must be depressed below the level of the left hemidiaphragm. Case description/methods: A 75 year-old-male presented with right sided flank pain for the past 9 months. He denied symptoms of nausea, vomiting, fever, chills, change in appetite, unexplained weight change, night sweats, melena or hematochezia. He reported chronic intermittent constipation, but he typically stooled daily or every other day. He had normal colonoscopy one year prior. Due to chronic nature of his pain, CT abdomen and pelvis was obtained. It showed anterior interposition of the hepatic flexure of the colon along the liver and right hemidiaphragm; this may be seen with Chilaiditi syndrome (Figure 1). Surgical correction was discussed, but conservative measures including diet, stool softeners, and exercise to promote weight loss and bowel regularity was instituted with resolution of gastrointestinal symptoms. Discussion: Patients with anatomical variants including absence, laxity, or elongation of the suspensory ligament are at increased risk for developing pathologic interposition. In patients with Chilaiditi syndrome, most common presenting symptoms abdominal pain, abdominal distention, nausea, emesis, constipation, and obstipation. The differential of Chilaiditi syndrome includes bowel obstruction, volvulus, intussusception, ischemic bowel, diverticulitis, appendicitis, subphrenic abscess, and pneumoperitoneum. In asymptomatic patients with Chilaiditi sign, treatment is usually conservative with stool softeners/laxatives and no interventions needed. Surgical intervention is indicated when the obstruction does not resolve with conservative management or there is evidence of bowel ischemia. The appropriate surgical approach depends on which segment of colon is interposed.Figure 1.: CT shows anterior interposition of the hepatic flexure of the colon along the liver and right hemidiaphragm.

S2384 Recurrent GI Bleeding From Colo Pancreatic Fistula – A Rare Entity

Introduction: Acute pancreatitis is an acute inflammatory condition affecting the pancreas. Colonic complications rarely occur with acute and chronic pancreatitis. Localized ileus, obstruction, colonic ischemia, hemorrhage and fistula formation have been reported together with acute pancreatitis. Colo-pancreatic fistula occurs at a rate of 3% to 10% in patients with severe acute pancreatitis. Here, we discuss the case of a patient with recurrent GI bleeding from a colo-pancreatic fistula. Case Description/Methods: A 62-year-old White male with past medical history of COPD, CAD s/p PCI, history of paroxysmal atrial fibrillation on Eliquis, diabetes presented with complaints of bleeding per rectum. He denied any other complaints. MRI abdomen showed pancreatic pseudocyst with possible fistulization of the pancreatic pseudocyst to the proximal descending colon (Fig 1A). Patient underwent EGD and colonoscopy. Colonoscopy showed evidence of pancreatico enteric fistula distal to the splenic flexure, the remnants were cleared on lavage and patient was discharged once stable (Fig 1B). One month later patient presented with another episode of recurrent GI bleeding he required 2 units of PRBC given the prior findings on the colonoscopy, patient was referred to pancreatic surgeon for further intervention of the colo-pancreatic fistula. Discussion: CPF is a rare condition associated with high mortality in patients with acute pancreatitis. Abdominal CT with or without contrast is often used for diagnosis; however, colonoscopy is also used to detect CPF. Given the anatomical proximity of the left part of the colon to the pancreas, CPF is commonly seen on the left side. Patients present with symptoms such as nausea, abdominal pain, vomiting and gastrointestinal bleeding. In contrast to other pancreatic enteric fistulas, CPF is associated with a high risk of severe hemorrhage, perforation or infection. Unlike other pancreatic enteric fistulas CPF do not close spontaneously, surgery is often the recommended treatment; however, less invasive endoscopic interventions, such as those using conventional hemoclips or over the scope clip, have been reported to have successful outcomes.Figure 1.: Fig 1A: MRI Abdomen showing pancreatic pseudocyst (shown by two blue arrows). Fig 1B: Colonoscopy showing fistulous opening in the descending colon distal to splenic flexure (shown by black arrow).