Colonic Mass Research Articles

A Mixed Neuroendocrine/Non-Neuroendocrine Neoplasm Arising in the Background of Ulcerative Colitis: A Case Report and Review of the Literature

Patient: Female, 57-year-old Final Diagnosis: Mixed neuroendocrine non-neuroendocrine neoplasm • ulcerative colitis Symptoms: Abdominal pain • distention • obstruction Medication: — Clinical Procedure: Laparoscopic diverting loop colostomy and colonic mass biopsy • open laparotomy and total colectomy with end ileostomy Specialty: Surgery Objective: Rare coexistence of disease or pathology Background:Inflammatory bowel disease (IBD) is a chronic, potentially life-long, disorder, including ulcerative colitis (UC) and Crohn’s disease (CD). Ulcerative colitis (UC) is an idiopathic chronic inflammatory disorder affecting the mucosa of the colon; it starts at the rectum and continues proximally in a continuous pattern to include up to the entire colon, called pancolitis. Patients with ulcerative colitis are at particularly higher risk of developing colorectal cancer (CRC) than the general population. Adenocarcinoma is the most common type of colorectal malignancy reported in the general population and IBD patients. One of the rarest types reported are the neuroendocrine neoplasms (NENs), which account for only 1% of all colorectal cancers, and it is very infrequent in IBD patients. Moreover, mixed neuroendocrine/non-neuroendocrine neoplasm (MiNEN) is a rare aggressive subtype of NENs that involves the colon in the background of an underlying chronic inflammatory process.Case Report:A 57-year-old woman, known to have long-term cirrhosis and ulcerative colitis, came to the Emergency Department with a suspected large-bowel obstruction. Imaging (CT scan of the abdomen) showed an obstructive transverse colon mass along with multiple descending colon masses. Biopsy of the transverse tumor confirmed the diagnosis of mixed neuroendocrine/non-neuroendocrine neoplasm (MiNEN).Conclusions:Although neuroendocrine tumors are rare, strong association exist between MiNENs and ulcerative colitis. Further studies and reports can help better understand the pathogenesis, diagnosis, management, and prognosis of these cases.

Primary Colonic Diffuse Large B-Cell Lymphoma in Bloom Syndrome

ABSTRACT Bloom syndrome is an inherited disorder involving a characteristic phenotype of short stature, photosensitive rash, immunodeficiency, and an early predisposition to various cancers, including lymphoma and colorectal neoplasms. We present a patient with Bloom syndrome found to have a colonic mass secondary to diffuse large B-cell lymphoma highlighting the importance of cancer screening and surveillance in these patients.

Colorectal adenocarcinoma with enteroblastic differentiation: diagnostic challenges of a rare case encountered in clinical practice

Colorectal adenocarcinoma with enteroblastic differentiation (CAED) is a rare subtype of colonic adenocarcinoma characterized by increased α-fetoprotein (AFP) production and the expression of at least one enteroblastic marker including AFP, glypican 3 (GPC3), or Spalt like transcription factor 4 (SALL4). We report a case of a 26-year-old female who presented with low back pain and constipation which persisted despite supportive measures. Imaging revealed multiple liver lesions and enlarged retroperitoneal nodes. Tumor markers including AFP were markedly elevated. On biopsy, samples from the liver revealed infiltrating glands lined by columnar-type epithelium with mostly eosinophilic granular to focally clear cytoplasm. By immunohistochemistry, the tumor showed immunoreactivity with AFP, hepatocyte antigen, GPC3, SALL4, CDX2, SATB2, and cytokeratin 20. A colonoscopy performed subsequently revealed a mass in the sigmoid colon and biopsy of this mass revealed a similar histology as that seen in the liver. A diagnosis of CAED was made, following the results of gene expression profiling by the tumor with next-generation sequencing which identified pathogenic variants in MUTYH, TP53, and KDM6A genes and therefore supported its colonic origin. Cases such as this underscores the use of ancillary diagnostic techniques in arriving at the correct diagnosis in lesions with overlapping clinicopathologic characteristics.

Prostate Cancer Masquerading as Colon Adenocarcinoma

A 91-year-old man with a 2-year history of prostate cancer (Gleason 8) treated with external radiation and androgen-deprivation therapy presented with nausea, vomiting, and abdominal pain. Computed tomography scanning of the abdomen showed intestinal air fluid levels and a mass in the descending colon. Colonoscopy confirmed the descending colon mass, which was partially circumferential, firm, and friable (Figure A, arrows). A colon adenocarcinoma was suspected, but initial biopsy was nondiagnostic.

Multifocal diffuse large cell neuroendocrine carcinoma of the colon

Large cell neuroendocrine carcinomas (LCNEC) of the colon are an extremely rare and aggressive type of colorectal cancer. While multifocality is more frequently seen in small intestine NECs, no cases of multifocal NEC of the colon have been reported before. A 69-year-old male patient presented with abdominal pain. Colonoscopy revealed a necrotic-polypoid mass in the sigmoid colon and the biopsy result was reported as malignant epithelial tumor. Laparoscopic anterior resection was performed with the preliminary diagnosis of colon adenocarcinoma. Histopathological examination revealed three polypoid tumors, the largest of which was 4 cm, in the sigmoid colon. Immunohistochemical examination showed positivity for synaptophysin, chromogranin, and CDX2. High Ki67 proliferation index, high mitosis, and widespread p53 expression were observed in all tumors. With these findings, a diagnosis of multifocal large cell NEC was made. To the best of our knowledge, this is the first report describing a case of multifocal large cell NEC of the colon. LCNECs of the colon are very aggressive. Here, we report for the first time a case of multifocal LCNEC. In a short period of 1 month after the surgery, new widespread metastases were detected in the liver. Therefore, these tumors should be followed more closely than usual for early treatment.

LAPAROSCOPIC LADD'S PROCEDURE IN A 58YR FEMALE WITH TRANSVERSE COLON TUBERCULOSIS MASS WITH MALROTATION - A RARE CASE REPORT

Intestinal malrotation is partial or complete failure of 270% counterwise rotation of midgut around the superior mesenteric vessels in embryonic life. Malrotation can present in any age group. Most of the patients present within rst month of life. However late presentation is rare, we present a case report of 58 yr female with tuberculosis transverse colon mass with malrotation with ladd's band with sub acute intestinal obstruction. She presented with epigastric pain,mass and vomiting. Patient underwent laaproscopic ladd's procedure and descending colon and ileum bypass with Ileo Descending anastomosis , She had good postoperative recovery. In this article we describe our experience in creating descending colon and ileum bypass with Ileo Descending anastomosis.

Retracted: Lovastatin Inhibits RhoA to Suppress Canonical Wnt/β-Catenin Signaling and Alternative Wnt-YAP/TAZ Signaling in Colon Cancer

Statins are first-line drugs used to control patient lipid levels, but there is recent evidence that statin treatment can lower colorectal cancer (CRC) incidence by 50% and prolong CRC patient survival through mechanisms that are poorly understood. In this study, we found that the treatment of APCmin mice by the mevalonate pathway inhibitor lovastatin significantly reduced the number of colonic masses and improved hypersplenism and peripheral anemia. Furthermore, reverse transcription polymerase chain reaction (RT-PCR) analysis of colonic mass tissues showed a potent inhibitory effect in both Wnt/β-catenin signaling and YAP/TAZ signaling in the lovastatin treatment group. The results of our transcriptomic analyses in RKO indicated that lovastatin regulated several proliferation-related signaling pathways. Moreover, lovastatin suppressed important genes and proteins related to the canonical Wnt/β-catenin and alternative Wnt-YAP/TAZ signaling pathways in RKO and SW480 cells, and these effects were rescued by mevalonic acid (MVA), as confirmed through a series of Western blotting, RT-PCR, and reporter assays. Given that statins suppress oncogenic processes primarily through the inhibition of Rho GTPase in the mevalonate pathway, we speculate that lovastatin can inhibit certain Rho GTPases to suppress both canonical Wnt/β-catenin signaling and alternative Wnt-YAP/TAZ signaling. In RKO cells, lovastatin showed similar inhibitory properties as the RhoA inhibitor CCG1423, being able to inhibit β-catenin, TAZ, and p-LATS1 protein activity. Our results revealed that lovastatin inhibited RhoA activity, thereby suppressing the downstream canonical Wnt/β-catenin and alternative Wnt-YAP/TAZ pathways in colon cancer cells. These inhibitory properties suggest the promise of statins as a treatment for CRC. Altogether, the present findings support the potential clinical use of statins in non-cardiovascular contexts and highlight novel targets for anticancer treatments.

A unique method for management of benign colonic masses: case report

Even though lipomas are most common non-epithelial tumors of the large intestine, they mostly present with non-specific symptoms. Intussusception is the most common morbidity related to such lesions and may present as intestinal obstruction. We present here a case of a young female who presented to gastroenterology department as a case of pain abdomen and nausea and a provisional diagnosis of subacute intestinal obstruction was kept. Contrast enhanced CT confirmed a diagnosis of intussusception due to an ascending colon mass? likely lipoma. The colonoscopy was done and biopsy was taken which was non-specific for malignancy. Patient, after taking due consent, was taken for surgery and laparoscopic assisted submucosal excision of lipoma was done and we will discuss the same. Endoscopic excision of lipomas has been reported but when failed, mostly segmental resection of the colon has been reported. To the best of our knowledge, this is the second reported case of laparoscopic assisted colotomy with submucosal excision of an intussuscepting colonic lipoma and first one in ascending colon.

Persistent Clostridium Difficile Diarrhea, Thinking Beyond Pseudomembranous Colitis: A Case Report

The prevalence of Clostridium difficile infection (CDI) is increasing along with the availability of diagnostic tests and is becoming a common nosocomial infection. CDI is the cause of nearly all occurrences of pseudomembranous colitis as well as 10-25% of antibiotic-related diarrhea. In patients presenting with persistent C. difficile diarrhea, the most common cause is the recurrence of pseudomembranous colitis but other differential diagnoses may need to be considered. In this case, we report a case of C. difficile diarrhea associated with life-threatening colitis and bowel ischemia.We report the case of a 60-year-old male with persistent C. difficile diarrhea complicated by bowel ischemia. He presented with one month of persistent diarrhea and vomiting that had been worsening over the past three days; these symptoms were precipitated with prolonged antibiotic use. The patient was not known to have any chronic diseases but was attending the oncology outpatient clinic for an undiagnosed colonic mass that needed further examination. The patient’s vitals showed tachycardia (116 bpm), and a palpable left lumbar mass was noted on examination. The patient’s laboratory tests revealed significantly high inflammatory markers and deranged renal functions, and x-ray images showed hemicolitis. The patient was admitted because of dehydration. Computed tomography (CT) of the abdomen was conducted which revealed bowel ischemia.A high index of suspicion for bowel ischemia should be held in C. difficile cases presenting with persistent symptoms. C. difficile infection is a very common healthcare-associated infection, its risk factors are older age, hospitalizations, and severe diseases. There is a need to increase the awareness of clinicians and prompt the diagnosis if suspicion of complicated C. difficile is present such as bowel ischemia.

The Importance of CT Pneumocolon in Detecting Colonic Lesions

Background: Colonic masses are clinically important because some of them are malignant and others have a tendency to become malignant such as polyps. CT pneumocolon may have a role in the evaluation and diagnosis of these masses. Objective: To determine the accuracy of computed tomography (CT) pmeumocolon in the detection of colonic masses compared with colonoscopy. Patients and Methods: A total of 60 patients with colorectal symptoms underwent evaluation for the presence of colorectal neoplasms by using both colonoscopy and CT pneumocolon and a comparison was made between them. Results: On colonoscopy, 10 out of 60 patients were having a negative colonoscopy. The results of colonoscopy of the other 50 patients were as follow; three out of fifty colonoscopies revealed invasive colorectal carcinomas in threse patients. The remaining 47 colonoscopies for 47 patients revealed benign polyps. The sizes of these polyps were as follows; (6 polyps were ˃1 cm in diameter), (17 polyps were 6-9 mm), and (24 polyps were ≤5 mm). CT pneumocolon detected all 3 malignant masses seen and biopsied by colonoscopy, but only (28 single polyps) which according to their size (4 polyps were ≥ 1cm), (11 polyps were 6-9 mm) and (13 polyps ≤5 mm), this gives CT pneumocolon a sensitivity of (63%), specificity of (70%) and accuracy (63%). Conclusion: CT pneumocolon has high sensitivity and specificity for a detection of large-sized masses, but not for small ones. CT pneumocolon may be suitable for investigating patients with symptomatic colorectal masses noninvasively. Keywords: Pneumocolon, colonoscopy, polyp, colonic carcinoma

The Relationship Between Severity of Gastric Inflammation Due to Helicobacter pylori and Colorectal Malignancies

Objective: Several factors play role in colorectal carcinogenesis. Among these factors, helicobacter pylori infection is supposed to be one of the causative factors. Previous studies were focused on investigation of the relationship between helicobacter pylori existence and colon carcinomas by particular serological diagnostic tests. The aim of our study was to determine the effect of the helicobacter pylori infection and the severity of inflammation related to this infection on the colon carcinomas and non carcinoma colon mass lesions(tubular adenoma, tubulovillous adenoma, hyperplastic polyp). Method: A retrospective study was conducted at Kecioren Teaching - Research Hospital between 2010 to 2018. The files of 657 patients who underwent colonoscopy and were diagnosed as colon benign or malign mass lesions were examined retrospectively from the hospital database. Two hundred five patients who had undergone both upper gastrointestinal endoscopy and colonoscopies were included in the study. The presence and severity of inflammation due to helicobacter pylori were evaluated by histopathological examination of biopsies taken during upper gastrointestinal endoscopy. The severity of H. pylori inflammation was graded according to the Sydney classification Results: In the comparison of colon carcinoma with other colon mass lesions group, there was no statistical significance in terms of gender (P= 0.094) and H. pylori serology (P= 0.998). However, the degree of inflammation was significantly high in patients with colon carcinoma than other colon mass lesions (P< 0.001). Conclusions: The fact that the severity of helicobacter pylori inflammation is higher in patients with colon carcinoma than patients with non-carcinoma colonic mass lesions suggests that inflammation due to helicobacter pylori may be more important than the presence of helicobacter pylori in the carcinogenesis of colon cancer.

Giant Paraesophageal Hernia With Obstructing Splenic Flexure Mass in the Left Hemithorax.

Giant paraesophageal hernias contain greater than fifty percent of the stomach above the diaphragm. Over fifty percent of large bowel obstructions are due to colorectal adenocarcinoma. Here, we present a rare case of a 69-year-old female patient who developed a closed loop colonic obstruction caused by a colonic mass in the distal transverse colon within a giant paraesophageal hernia. We successfully performed emergent paraesophageal hernia reduction and mesh repair with extended right hemicolectomy and ileocolonic anastomosis. Emergent hernia repair via an abdominal approach can be used in this setting.

Case of a Vanishing Colonic Mass.

ABSTRACTColonic ischemia most often presents with abdominal pain and rectal bleeding. Presentation of colonic ischemia as a prominent mass is exceptionally unique and is not often reported. Concern for neoplasm prompted a repeat scope, which revealed the mass had vanished. We present a case of colonic ischemia, which produced a transient colonic mass formed by inflammatory tissue and clots.

Incidental Colonic Masses and Cytomegalovirus (CMV) Infection in a Treatment- Naïve Chronic Lymphocytic Leukemia Patient without GI symptoms

Abstract Introduction/Objective Gastrointestinal (GI) involvement by leukemia ranges from 5.7 to 13 % with very few published reports describing infiltration of the GI tract by chronic lymphocytic leukemia (CLL). GI bleeding, abdominal pain, and obstruction have been described as presenting symptoms of GI involvement. Yet, discrete lesions are rare. Infection is a common complication in patients with CLL. In untreated patients, these infections are typically by encapsulated bacteria involving the respiratory tract and associated with hypogammaglobulinemia. Viral infections often happen after therapy. This report presents a patient with a history of treatment- naïve CLL and HSV who presented for colostomy reversal and was incidentally found to have two partially obstructing colonic masses, as well as cytomegalovirus (CMV) infection. Methods/Case Report This is a 78-years-old female with treatment-naïve CLL and past medical history of hypertension, atrial fibrillation, diverting colostomy secondary to chronic perineal HSV-2 ulcer and recent perirectal abscess. She presented for colostomy reversal in the absence of any reported GI symptoms at that time. Labs showed leukocytosis; WBCs count of 25 K/MM3, anemia and neutropenia. Endoscopic studies incidentally discovered two partially obstructing masses in the ascending and transverse colon that were biopsied. A right hemicolectomy and colostomy closure were followed, and the patient was discharged on valganciclovir. Results (if a Case Study enter NA) Histopathological examination demonstrated mucosal ulceration with viral cytopathic changes and positive CMV IHC stain. In addition, a dense atypical, small sized lymphoid cell infiltrate with no sheets of large cells or confluent necrosis were identified. Flowcytometry and IHC stains showed aberrant CD5+ B cells with CD23 co-expression consistent with the patient’s history of CLL. Conclusion The case describes the unique presentation of a patient with treatment- naïve CLL without any GI symptoms, yet was incidentally found to have colonic involvement by CLL forming discrete colonic masses as well as CMV and HSV infections. Since she is untreated, her infections (HSV and CMV) are likely secondary to being immunocompromised by CLL and neutropenia. In conclusion, although rare, GI involvement by CLL should be considered in treatment naïve CLL patient’s and concomitant infections should be evaluated.

A Rare Case of Rectal Mixed Adeno-Neuroendocrine Carcinoma (MANEC) with Liver Metastasis

Abstract Introduction/Objective Mixed Adeno-Neuroendocrine Carcinoma (MANEC) is a rare subtype of colorectal cancer which was recognized and described by the world health organization (WHO) in 2010. It was defined as malignant neoplasms in which each component represents at least 30% of the lesion. In this abstract, we present a case of mixed adeno-neuroendocine carcinoma of the rectum with metastasis of the neuroendocrine component to the liver. We discuss the histomorphological and immunohistochemical features of this tumor. Methods/Case Report A 64-year-old male presented with abdominal pain in the right upper quadrant area. An abdominal CT scan showed multiple nodules in the liver as well as a mass lesion in the rectum. Liver needle core biopsy revealed infiltrating nests of atypical cells with marked pleomorphism, a variable amount of cytoplasm, and prominent nucleoli. Mitotic activity and necrosis were seen. By immunohistochemical staining, the tumor cells were negative for CK7 and CK20, positive for CD56, and partially positive for CDX2. Although glands formation was not seen; however, given the positivity of CDX2 as well as the colonic mass, mismatch protein analysis (MMR) was performed and it was intact. These findings were consistent with poorly differentiated high-grade neuroendocrine carcinoma. The rectal mass was excised through colonoscopy and revealed invasive carcinoma with morphology similar to that of the liver biopsy in addition to a vague glandular differentiation. Tubulovillous adenoma was also seen. On immunohistochemical staining, the invasive component was positive for CD56, synaptophysin, and chromogranin A, partially positive for CDX2, and negative for CK20, consistent with the neuroendocrine component. The adenoma was positive for CK20, and CDX2, and negative for CD56. Rare positivity was seen by synaptophysin and chromogranin A. The carcinoma and the adenoma were both positive for P53. The neuroendocrine carcinoma comprised 40-50% of the tumor. Results (if a Case Study enter NA) NA Conclusion Only a few cases of Mixed Adeno-Neuroendocrine Carcinoma (MANEC) were reported. We add a new case with liver metastasis. The systematic application of immunohistochemical studies aided in the recognition of each component of the neoplasm.

EP.TH.717Triple tumour: A myriad of serial incidental findings in a patient presenting with Gallstone pancreatitis

Abstract Aim To present a rare incidental synchronous triple tumours - colonic adenocarcinoma, endometroid ovarian adenocarcinoma and benign Brenner tumour in a patient admitted with acute gallstone pancreatitis. Methods A 75-year-old female presented with epigastric pain. Blood-tests and USS abdomen confirmed gallstones and pancreatitis. She was treated conservatively. USS also showed incidental pelvic mass which was further characterised by CT and MR scans. These scans confirmed heterogeneous lobulated mass in the left adnexa. CT scan also picked-up incidental mass in transverse colon, which was confirmed as cancer by colonoscopy. She was offered therapeutic resection after discussion in Colorectal and Gynaecology MDT. Intra-operatively, transverse colonic tumour was invading into the proximal ileum. Laprascopic surgery concluded with extended right hemicolectomy, small bowel resection-anastomosis, omentectomy, total abdominal hysterectomy and bilateral salpingo-oophorectomy. Results The patient had gradual recovery without any complications. Histopathology showed T4N2 poorly differentiated adenocarcinoma of colonic mass, FIGO grade 1 stage 1c endometrioid adenocarcinoma of left ovary and benign brenner tumour of right ovary. Post-operative MDT did not offer adjuvant-therapy due to slow recovery and fraility. So far, two-years of follow-up did not show any recurrence. Conclusion This report adds to the limited literature of triple synchronous tumours, including rare Brenner accounting for 5% of benign ovarian tumours and endometrioid ovarian tumour with an incidence of 4 -7%. Multi-disciplinary approach and combined surgery can achieve a desirable outcome in such complex cases. It is crucial to identify the primary status of the tumours as it will guide the adjuvant treatment.

Probiotics alleviate inflammatory bowel disease in mice by regulating intestinal microorganisms-bile acid-NLRP3 inflammasome pathway.

The objective of the present study was to elucidate the mechanism of intestinal microorganisms- bile acid- NLRP3 inflammasome regulation in mice with inflammatory bowel disease treated with probiotics. The abnormal activation of NLRP3 inflammasome is the main pathogenic factor that leads to the development of chronic colitis in IL-10-/- mice. In this study, we divided the IL-10-/- and wild-type mice on a C57BL/6 background into 3 groups: control group (wt mice, n=10), IBD group (IL-10-/- mice, n=10), and probiotic group (IL-10-/- mice treated with probiotics, n=10). The analyses included mRNA levels of cytokines and protein expression of NLRP3 inflammasome and NOD2, as well as colorimetric determination of Wnt, Notch and BMP activity in colon tissue and fresh colon mass. The fresh colon mass was increased in the IBD mice when compared with the control and the probiotic groups (P<0.05). The histological score of the proximal colon in the IBD group was higher than in two other groups (P<0.05). The probiotic group showed lower levels of IFN-γ, IL-17F, IL-1α and IL-25 mRNA compared to the IBD group (P<0.05). The main components of NLRP3 inflammasome (NLRP3, ASC, caspase-1 and IL-1β) and NOD2 were increased in IBD group compared to the control, and decreased after probiotic treatment (P<0.05). FXR, TGR5, vitamin D, and CAR were all increased in IBD group compared to the control and probiotic groups (P<0.05). In conclusion, probiotics modulated the intestinal microbial-bile acid-NLRP3 inflammation in IBD mice.

830 A Case of Colo-Colonic Intussusception Secondary to A Large Lipoma in An Adult

Abstract Colonic lipomas are benign tumours, most commonly in the right colon or caecum, usually detected incidentally at colonoscopy and are often asymptomatic not requiring treatment. Lipomas leading to intussusception have previously been described in case reports, but it remains a rare occurrence, no specific incidence data has been documented. We present the case of a patient with a 7cm colonic lipoma that developed an intussusception. This patient suffered non-specific pulling pain along the right and upper abdomen for many years. A distal ascending colonic lipoma was identified, on repeated imaging and colonoscopy and biopsied. It was concluded that the abdominal pain was due to gallstones, diverticulitis and adhesions from previous pelvic surgery. In early December 2020, the patient was reviewed and listed for elective cholecystectomy. Later the same month, the patient was admitted with severe abdominal pain, watery and bloody diarrhoea. CT scan showed the colonic lipoma had acted as the lead point for an intussusception, with the lipoma and surrounding colon having intussuscepted into the transverse colon. Patient had an open right hemicolectomy and anastomosis for colo-colic intussusception secondary to the lipoma. Subsequently, the patient developed anastomotic breakdown requiring relook laparotomy with resection of ileo-colic anastomosis and end ileostomy formation. Adults presenting with intussusception is rare and associated with nonspecific signs and symptoms. Variability in clinical presentation highlights the need for a low index of suspicion in people with known colonic masses. In addition, early surgical intervention should be considered in masses &amp;gt;4cm as previously suggested in the literature.

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.

S1812 Colonic Hemangioma Masquerading as Colonic Mass – Endoscopic Dilemma to Resect or Not?

S1812 Colonic Hemangioma Masquerading as Colonic Mass – Endoscopic Dilemma to Resect or Not?