Pelvic CT Scan Research Articles

The supra-pectineal quadrilateral surface buttress plate for the treatment of complex acetabular fractures

Objective To introduce a novel anatomical supra-pectineal quadrilateral surface buttress plate, and explore its advantages, disadvantages and clinical efficacy in the treatment of complex acetabular fractures. Methods Data of eighteen cases of acetabular fractures treated in our department from March 2017 to March 2019were retrospectively analyzed. There were 15 males and 3 females with an average age of 49.6 years (range, 27-62 years). According to the Letournel-Judet’s classification, there were 3 cases of anterior column fractures (involving quadrilateral surface), 2 cases of T shaped, 8 of cases anterior column and posterior hemi-transverse (ACPHT) and 5 cases of double columns fractures. The time from injury to operation was 5-14 days (mean, 7 days). Before operation, all patients were taken pelvic anterior-posterior X-ray and CT scan. All patients were adopted supra-ilioinguinal approach and fixed by supra-pectineal quadrilateral surface buttress plate. Surgical time, intraoperative blood loss and postoperative complications were collected. After operations all patients were taken pelvic X-ray in anterior-posterior and Judet position, as well as CT scan. The radiographic quality of reduction was evaluated by Matta criteria and hip functions were evaluated by Matta Modified Merle d’Aubigne-Postel scoring system. Results The average surgical time was 130 min (range, 100-200 min). The average blood loss was 560 ml (range, 400-900 ml). An additional shaping was unnecessary in 18 patients who were implanted with the anatomical supra-pectineal quadrilateral surface buttress plate and all patients were operated successfully. All patients were followed up for an average time of 9 months (range, 6-15 months). The quality of fracture reduction was evaluated according to Matta standard, of which there were 11 cases excellent, 4 cases good, and 3 cases poor, with an excellent rate of 83.3% (15/18). At the latest follow-up, the function of the hip joint was evaluated according to the Matta Modified Merle d’Aubigne-Postel scoring system for a mean of 15.8 scores (range, 12-18 scores), of which there were 10 cases excellent, 6 cases good, 2 cases fair, with an excellent rate of 88.9% (16/18). All patients recovered well, and there were 2 cases of lateral femoral cutaneous nerve injury postoperative who had recovered one month later. There was no other postoperative complications. Conclusion The anterior and posterior column and quadrilateral surface could be stabilized simultaneously by the anatomical supra-pectineal quadrilateral surface buttress plate without intraoperative shaping. Moreover, it is more likely to obtain a satisfactory clinical outcome by using this special plate with lower complications and rigid fixation. Therefore, it is a kind of internal fixation method worthy of promotion in the treatment of complex acetabular fractures. Key words: Acetabulum; Fractures, bone; Fracture fixation, internal; Internal fixators

Large retroperitoneal dermoid cyst in a 55 year old lady: a rare case report

Retroperitoneal cysts are usually rare asymptomatic lesions but may present with unspecific symptoms depending on the size, location and complications such as hemorrhage, infection, or rupture. A 55-year-old lady presented with complaints of non-obstructed umbilical hernia. CT scan of abdomen and pelvis was done suggestive of a large cystic non-enhancing thin walled lesion of size 27×15 cm in right lumbar region. Intraoperatively, there was a large mesenteric cyst from retroperitoneum of size 25×15 cm, extending from right iliac fossa up to right hypochondrium. A confirmatory diagnosis of dermoid cyst was made following histopathology. Retroperitoneum is a rare site for dermoid cyst. Retroperitoneal cysts which develop within the retroperitoneal space are rare intra-abdominal tumours with an incidence of 1 per 1,40,000. The incidence of recurrence for retroperitoneal cysts is higher than with other forms of cysts because their proximity to major blood vessels and other organs makes them difficult to completely excise. Surgical resection is indicated to establish a diagnosis and prevent eventual complications. Complete excision of tumour is necessary due to the risk of malignancy. After complete surgical resection the 5 years survival rate is nearly 100%.

87 A gynaecological cause of right heart failure

Abstract Introduction A 68-year-old lady complained of pelvic pain associated with progressive abdominal distension over few months. Physical examination revealed ascites, smooth hepatomegaly and lower limb edema. CT scan of abdomen and pelvis showed a 4 cm x 5 cm right ovarian mass without other intraabdominal lesion. Surgical excision of the ovarian mass was performed with clear resection margin. The ascitic fluid was negative for malignant cells. However, the patient had persistent ascites and lower limb edema after surgery. The gynaecologist suspected that she might have cardiac problems. Procedure Transthoracic echocardiogram was performed. The right atrium and ventricle were markedly enlarged. The tricuspid valve leaflets appeared retracted and sclerotic, with failed coaptation during systole (Figure A), severe tricuspid regurgitation (Figure B) and marked dilatation of inferior vena cava without respiratory variation. The pulmomary valve was not well visualized on 2D images. Continuous wave Doppler across pulmonary valve demonstrated short pressure half time 66 msec and premature termination of diastolic flow (Figure C), suggestive of severe pulmonary regurgitation. There was no intracardiac shunt. Left sided valves were unremarkable. Additional tranesophageal echocardiogram allowed better assessment of pulmonary valve, which revealed one of the cusps to be thickened, retracted and immobile on real time 3D images (Figure D, arrow). Discussion The ovarian mass was confirmed to be a carcinoid tumour. Due to its direct drainage into systemic venous circulation the vasoactive substances (serotonin, prostaglandin etc) reach the right heart directly without being metabolized by liver, resulting in plaque like deposit of fibrous tissue on the endocardium and valve surfaces, leading to classical appearance of thickened, retracted and immobile leaflet and subsequent valvular regurgitation or, less commonly, stenosis. Left-sided valve disease is less common, and may occur in cases of bronchial carcinoid or in presence of atrial right to left shunt (e.g. PFO). Urinary 5-hydroxyindoleacetic acid (5-HIAA) is a useful non-invasive diagnostic test. Carcinoid heart disease usually does not regress even the tumour is treated, and valve replacement is the only definitive curative treatment. This lady received tricuspid and pulmonary valve replacement with subsequent symptom resolution and chest X-ray showed marked reduction of cardiomegaly (Figure E). Conclusion A baseline echocardiogram is recommended for assessment valvular involvement in patient with carcinoid tumour, as the cardiac symptoms may be mistaken to be related to regional spread of tumour. Pulmonary valve is very often the "forgotten" valve in many Echo studies. However, it is crucial to have detailed assessment (with aids by 3D images or TEE) due to its implication to the surgical treatment planning. Abstract 87 Figure.

Correlation of diaphragm surgical findings with preoperative CT scans in ovarian cancer

Objective: Correlation of diaphragm surgical findings in ovarian cancer patients with and without diaphragm metastases with pre-operative CT diaphragm findings to assess sensitivity and specificity for diaphragm disease. Material and Methods: A retrospective study of 120 ovarian cancer patients (60 with and 60 without diaphragm metastases at surgery), FIGO Stage IIIC or IV, undergoing cytoreductive surgery at Mayo Clinic, Arizona, between January 2000 and October 2014. All patients had preoperative imaging with CT scan of abdomen and pelvis including the lower lung fields. CTs were not reviewed retrospectively. Results: Among 60 patients with diaphragm metastases, preoperative CTs were positive for diaphragm disease in 17 patients, with a sensitivity rate of 28% (CI 95%: 0.17- 0.41). All 60 patients with no diaphragm metastases had negative CTs, with a specificity of 100% (CI 95%: 94.0%-100%). When analyzed by lesion size, CTs were negative in 66.7-80% of patients with diaphragm lesions ranging from 1-15 mm. There was a trend towards increased detection rate with increasing size of lesions, but it did not reach significance (p = 0.529). CT detection rate for single metastatic lesion was 18.2% (6/33) and for multiple lesions it was 25.9% (7/27). There was no difference for CT identification of right, left, or bilateral metastases (p = 0.399). The sensitivity and specificity of CT for pleural effusion was 100% (CI 95%: 72.2%-100%) and 88% (CI 95%: 76.2%- 94.4%), respectively. The area under the receiver operating characteristic (ROC) curve was 0.680 (CI 95%: 55.3%-72.2%) for CT detection of diaphragm metastases and 0.957 (CI 95%: 79.9%-95.3%) for pleural effusions. Conclusion: CT has a low sensitivity and a high specificity for the prediction of diaphragm metastases in ovarian cancer. The size, location, and number of diaphragm lesions do not significantly improve CT detection rate.

Lofgrenov sindrom i zahvaćenost slezine - prikaz slučaja

Löfgren's syndrome is an acute form of sarcoidosis characterized by fever, erythema nodosum (EN), bilateral hilar lymphadenopathy (BHL), and polyarthritis. This syndrome is a self-limiting disease. A 45-year-old woman was admitted to our hospital complaining of fever, visual blurring, and arthralgia. A chest radiograph showed bilateral hilar mass lesions. High-resolution computed tomography (HRCT) scans of the chest revealed multiple nodules at different segments of the lung, bilateral hilar and paraesophageal lymphadenopathy. Also, abdominal and pelvic CT scan showed mild splenomegaly, with multiple hypodense nodules in the spleen and an accessory spleen. She was diagnosed with Löfgren's syndrome.

Sacrée métastase!

Metastatic bladder tumors are dominated by ganglionic involvement, followed by that of bone, lung, liver and finally peritoneum. Bone metastases are located, in terms of frequency, in the thoracic, lumbar and cervical regions. Bone metastasis rarely affects the sacrum, most often characterized by large tumor volume and therefore surgery can be difficult. We here report the case of a 56-year-old diabetic patient receiving oral anti-diabetic agents presenting with an 8-month history of haematuria associated with pain in the sacrum persisting for 2 months. Clinical examination revealed increased right gluteal region volume associated with inflammatory signs (A). Pelvic CT scan showed tissue formation in the left side of the bladder with calcifications associated with bulky, osteolytic mass in the sacrum measuring 10 cm along its longer axis with thickening in the soft tissues that face this lesion (B). Biopsy showed urothelial carcinoma. The patient was referred to the Department of Oncology for systemic treatment.

Xanthogranulomatous Pyelonephritis A Review and Update of the Literature

Xanthogranulomatous pyelonephritis (XGP) is a rare chronic destructive granulomatous inflammatory process that affects sporadically the parenchyma of the kidney and the disease tends to be associated in many cases with long-term urinary tract obstruction, urinary tract infection and also in cases with calculi within the kidney. XGP does affect females more commonly in comparison with males, it does affect all age groups including newly born up to the elderly. Majority of the patients tend to be symptomatic and some of the symptoms could include: pyrexia, flank / loin / abdominal pain, palpable mass in loin/abdomen/costovertebral region, weight loss, visible haematuria. There may be associated diabetes mellitus, obesity, or immune deficiency. There may be anaemia and leucocytosis upon blood tests. Urine cultures may grow Escherichia coli, or proteus but in other situations the urine culture could be negative. Ultrasound scan of renal tract, CT and MRI scan of abdomen and pelvis tend to be undertaken in the assessments of patients. CT scan has globally been the establishment of radiology imaging diagnosis. Radiology imaging may demonstrate focal or diffuse XGP but the diffuse form is more common. It may reveal multiple low-attenuated cystic masses in the kidney, calculi in the kidney, hydronephrosis / dilated calyces / bear’s paw appearance in some cases. Macroscopy examination of the specimen of the kidney would tend to show multiple yellow nodules around calyces, and the lesion may form a mass or be infiltrative. Pathology examination of specimens of XGP would tend to show granulomatous inflammatory infiltrate that consists of neutrophils, lymphocytes, plasma cells, xanthomatous histiocytes, as well as multi-nucleated giant cells. Immunohistochemistry staining may show positive staining for CD68. Some of the differential diagnoses include: clear cell carcinoma of the kidney, papillary renal cell carcinoma, sarcomatoid renal cell carcinoma, leiomyosarcoma, malakoplakia of kidney, megalocystic interstitial nephritis, and renal replacement lipomatosis. Majority of diffuse cases have been treated by nephrectomy and antibiotics and some focal cases have been treated by partial nephrectomy and antibiotics but on very rare occasions cases have been treated by drainage of the abscess with biopsy and in conjunction with antibiotics. Percutaneous nephrostomy has also been undertaken pre-operatively to decompress the kidney by draining the abscess in the occasional case.

Leiomyoma of the Urinary Bladder: A Review and Update

Leiomyoma of the urinary bladder / leiomyoma of the ureter is a very rare benign tumour of smooth muscle origin which has been reported sporadically globally. Leiomyoma of the urinary bladder/ureter may be diagnosed incidentally during investigation of various conditions including infertility and hepatitis. Leiomyoma of the urinary bladder / ureter may manifest in female as well as in a male patient with non-specific symptoms including lower urinary tract symptoms / retention of urine, haematuria, loin pain/discomfort, urinary tract infections and cystitis. The general and systematic examinations may be normal but at times there may be a palpable mass within the area of the urinary bladder on bimanual examination but not always. There may occasionally be tenderness in the loin. The results of routine haematology and biochemistry blood tests would generally tend to be normal but there may be anaemia and impairment of renal function some cases of visible haematuria and obstruction of the ureter respectively. Ultrasound scan would tend to illustrate a well-circumscribed polypoidal soft tissue mass projecting into the urinary bladder or within the intramural area of the bladder. Intravenous urography would show a filling defect in the urinary bladder. CT and MRI scans of abdomen and pelvis with contrast would show a well-defined round mass in the area of the bladder which could be iso-tense to skeletal muscles on T1 and T2 weighted images and occasionally may show cystic areas of necrosis. Cystoscopy would show the lesion projecting into the urinary bladder at the specific area of the urinary bladder involved and at times the projecting lesion would be covered by normal looking urothelial mucosa and on other occasions when the lesion is large and in the area of a ureteric orifice the specific ureteric orifice would not be visualized. Diagnosis of leiomyoma of the urinary bladder / ureter would be confirmed upon histopathology and immunohistochemistry study features of trans urethral resection biopsies of the lesion which would tend to show smooth muscle spindled-cells with no evidence of atypia, or necrosis, or haemorrhage and associated with a low Ki67 index. Trans-urethral resection of the urinary bladder lesion tends to be undertaken for small to medium sized lesions with good outcome but this tends to be associated with about 18% recurrence rate that would require further resections or surgical excision to ensure complete removal of the lesion and no further recurrences. Surgical excision of the lesion including partial cystectomy, local excision / enucleation have been very effective for the treatment of larger leiomyomas with no reported recurrence so far; nevertheless, patients who undergo augmentation cystoplasty or total cystectomy and urinary diversion would need to cope with the functional problems related to the cystoplasty or urinary diversion. Differential diagnoses of leiomyoma of the urinary bladder / ureter include leiomyosarcoma, urothelial carcinoma and other malignant lesions affecting the urinary bladder. There is need for clinicians to explore minimal invasive surgery to treat patients who have leiomyoma of the bladder / ureter especially those who have multiple co-morbidities and the alterative management options that could be undertaken in multi-centre trials include: Cryotherapy, radiofrequency ablation, irreversible electroporation, high frequency ultrasound treatment and super-selective embolization of the arterial branch supplying the leiomyoma. Patients who develop ureteric obstructions would additionally require nephrostomy insertions or insertion of ureteric stents as a temporary measure to improve their renal functions.

Fluoroscopically guided acetabular posterior column screw fixation via an anterior approach.

ObjectiveSafe posterior column screw fixation via an anterior approach under two-dimensional fluoroscopic control.IndicationsAnterior column with posterior hemitransverse fractures (ACPHF); transverse fractures; two-column fractures and T‑type fractures without relevant residual displacement of the posterior column after reduction of the anterior column and the quadrilateral plate.ContraindicationAcetabular fractures requiring direct open reduction via a posterior approach; very narrow osseous corridor in preoperative planning; insufficient intraoperative fluoroscopic visualization of the anatomical landmarks.Surgical techniquePreoperative planning of the starting point and screw trajectory using a standard pelvic CT scan and a multiplanar reconstruction tool. Intraoperative fluoroscopically controlled identification of the starting point using the anterior–posterior (ap) view. Advancing the guidewire under fluoroscopic control using the lateral–oblique view. Lag screw fixation of the posterior column with cannulated screws.Postoperative managementPartial weight bearing as advised by the surgeon. Postoperative CT scan for the assessment of screw position and quality of reduction of the posterior column. Generally no implant removal.ResultsIn a series of 100 pelvic CT scans, the mean posterior angle of the ideal posterior column screw trajectory was 28.0° (range 11.1–46.2°) to the coronal plane and the mean medial angle was 21.6° (range 8.0–35.0°) to the sagittal plane. The maximum screw length was 106.3 mm (range 82.1–135.0 mm). Twelve patients were included in this study: 10 ACPHF and 2 transverse fractures. The residual maximum displacement of the posterior column fracture component in the postoperative CT scan was 1.4 mm (0–4 mm). There was one intraarticular screw penetration and one perforation of the cortical bone in the transition zone between the posterior column and the sciatic tuber without neurological impairment.

Isolated colon metastasis of vaginal cuff squamous cell carcinoma; a case report

Primary vaginal squamous cell carcinoma (SCC) is one of the rarest kinds of cancer in gynecological cancer. We report a 40-year-old presented with abdominal pain in her right lower quadrant with past-medical history of vaginal cuff SCC without any metastasis about 2.5 years ago which was treated with a combination of surgery and radiotherapy. Ultrasonography and abdomino–pelvic CT scan suggested an inflammatory phlegmon in RLQ probably due to a complicated appendicitis or malignancy. Ultrasonography-guided biopsy was performed which showed a poor differentiated SCC. Chest and abdominopelvic CTs showed no metastasis. Patients underwent laparotomy and ileocecal resection then end-to-end anastomosis was performed. A study of specimens showed a non-keratinizing SCC.

3012 Pancreatic Ascites in a Patient With Thromboembolic Disease

INTRODUCTION: Pancreatic ascites is a rare condition characterized by abdominal pain, weight loss and progressive ascites. It is a complication of pancreatic duct disruption leading to leakage into the peritoneal cavity. The epidemiology is not well studied, which makes diagnosis challenging for clinicians. CASE DESCRIPTION/METHODS: A 54-year old female with a history of alcohol abuse, alcoholic cirrhosis, and chronic pancreatitis with pseudocyst presented to the Emergency Department with pleuritic chest pain, right calf pain and swelling for several days. She also had chronic abdominal pain, nausea, vomiting and poor appetite with 10-pound weight loss in 3 months. Her pseudocyst was routinely followed up with no significant change. The patient's significant vitals included BMI of 14.45 kg/m2, tachypnea and tachycardia. Physical examination revealed epigastric tenderness, abdominal distension and right calf swelling. Significant labs included hypoalbuminemia 1.3 g/dL, D-dimer 13.68 mcg/mL and Pro-calcitonin 19.92 mcg/L. CTA of chest revealed bilateral pulmonary emboli with right heart strain. Lower extremity duplex was positive for right femoral DVT. Patient was subsequently started on heparin infusion. A CT scan of abdomen and pelvis revealed an unchanged 2.2 × 1.1 cm pseudocyst in head of pancreas. Diagnostic paracentesis showed fluid analysis of albumin 0.5 g/dl, protein 1.4 g/dl and elevated amylase 836 U/L. The SAAG score was 0.8, which was clinical congruent with pancreatic ascites. MRCP identified the pseudocyst having a thin tubular extension along anterior pancreatic body. ERCP with pancreatic duct sphincterotomy and stent placement did not provide clinical improvement. EUS visualized a 6.6 cm fluid collection between stomach and spleen, with the pseudocyst was 1 cm adjacent to the gastric wall. It was aspirated and metal stent was placed to dilate entry into pseudocyst via endoscopic cystogastrostomy. The fluid content was finally suctioned out. The patient clinically improved and was discharged on warfarin. The stent was removed a month later. DISCUSSION: This case illustrates the importance of immediate paracentesis in diagnosing pancreatic ascites, a rare and potentially fatal condition if left untreated. Diagnosis is made with elevated fluid amylase, low SAAG score and clinical picture congruent with chronic pancreatitis with accompanied pseudocyst or severe acute pancreatitis. Early endoscopic intervention has shown highly successful at reducing mortality, hospital length of stay and recurrence.

1657 Acute Drop in Hemoglobin Requiring Transfusion an Odd Presentation of Metastatic Breast Cancer to the Colon in Form of Colon Polyps

INTRODUCTION: Breast cancer (BC) is the leading cancer and second most common cause of cancer deaths in women. It can present with metastases to other organs. However, BC metastases to the colon are uncommon. Lobular carcinoma, comprising 10% of BC, is most commonly spread to gastrointestinal tract (GIT). We present a case of a patient whose recurrent metastatic lobular adenocarcinoma presented as colon polyps. CASE DESCRIPTION/METHODS: A 59-year-old female was diagnosed in 2006 with stage IIIC grade 1 estrogen (ER+), progesterone receptor positive (PR+), and HER-2/neu negative (Her2-) invasive lobular BC of left breast and treated with left modified radical mastectomy, chemo and radiation therapy to left chest wall. She was in remission since 2007 and on maintenance hormonal therapy. She presented in late 2018 with shortness of breath and fatigue secondary to anemia. She had a history of roux and Y gastric bypass. She was admitted to the hospital with symptomatic anemia, drop in HGB 8.3 to 5.5 though she received blood transfusion a week prior. A full hematologic workup was unrevealing including bone marrow biopsy. She required multiple transfusions and hospitalization in 2019. CT scan of abdomen and pelvis revealed no abnormality in the colon. She underwent EGD and colonoscopy. EGD revealed esophagitis and prior gastric bypass without evidence of bleeding. Colonoscopy revealed numerous polyps throughout colon, all removed. Pathology on these polyps showed metastases of ER+, PR+, HER2- BC. She underwent re-staging with biopsy of a para-aortic lymph node and skeletal survey, both of which showed metastatic disease. After colonoscopy with polypectomy her anemia improved. She has subsequently been started on palliative chemotherapy. DISCUSSION: This is a unique case of metastatic BC with severe anemia due to colonic metastases. To our knowledge, only a handful of case reports exist describing similar presentations. BC rarely metastasizes to GIT and when it does it spreads to the stomach as linitis plastica. Metastases of BC to the colon are less common, although there is a case reports metastatic BC being diagnosed based on a single colon polyp and colonic obstruction due to large metastatic masses. Our case highlights the importance of screening for GIT metastases that may not occur until many years after the initial BC diagnosis. Moreover, given the propensity of lobular BC to metastasize to GIT, more frequent screening endoscopies may be beneficial to these patients.

1511 Epiploic Appendagitis After Rigorous Exercise in a Woman: An Easily Misdiagnosed Cause of Acute Abdomen

INTRODUCTION: Acute abdominal pain can be a surgical emergency. However, benign etiologies, such as epiploic appendagitis (EA), can present with similar symptoms. We report a case of an otherwise healthy woman, on oral contraceptives (OCP), presenting with severe abdominal pain related to epiploic appendagitis. Timely recognition of this condition is important to avoid misdiagnosis and unnecessary surgical interventions. CASE DESCRIPTION/METHODS: A 44-year-old woman with a past medical history of ovarian cyst and BMI 25 presented to the Emergency Department with a three-day history of sharp left lower quadrant (LLQ) pain. Patient reported that she started a vigorous aerobic exercise regimen 6 weeks before. Only medication was norgestimate-ethinyl estradiol for contraception. Vital signs normal. Physical exam showed tender LLQ without rebound tenderness or rigidity. Initial testing including complete blood count, basic metabolic panel, pregnancy test, urinalysis, and vaginitis panel were unremarkable. Given worsening pain, CT scan of abdomen and pelvis with contrast was obtained showing an encapsulated oval, pericolonic fatty nodule adjacent to the sigmoid colon, with surrounding fat stranding consistent with EA. Patient was discharged home with conservative pain management. Her OCP was discontinued. She had no symptom recurrence within a 3-year period. DISCUSSION: EA is an uncommon cause of acute abdominal pain that mimics serious medical or surgical emergencies such as acute diverticulitis, appendicitis, or, gynecological emergencies such as ruptured ectopic pregnancy. It is, generally, a self-limited ischemic infarction involving the epiploic appendices, which are normal outpouching fat of the lower colon and rectum. EA can be divided into primary versus secondary. The primary form is caused by either torsion or spontaneous venous thrombosis of an epiploic appendage central draining vein. It commonly occurs in men aged 20–50. Risk factors include obesity, hernia, and rigorous exercise. Secondary form is related to inflammation of adjacent organs. Although our patient does not match the typical profile for EA, rigorous exercise and probably OCP usage, a risk factor for thromboembolic phenomena, may have triggered this episode. Diagnosis of EA is by imaging via ultrasound or CT scan, and complete resolution typically occurs within two weeks with conservative management. Prompt identification of EA is essential in patients at risk, to avoid unnecessary surgical procedures.

2739 A Rare Case of Multifocal Gastrointestinal Stromal Tumor

INTRODUCTION: Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors most often located in the stomach and proximal small bowel although they can occur in any part of the gastrointestinal tract and occasionally in omentum, mesentery, and peritoneum. GISTs are traditionally thought of as solitary tumors that rarely present with multiple lesions. We present a unique case of multifocal GIST that was incidentally found on imaging. CASE DESCRIPTION/METHODS: A 44-year old woman with no prior medical history presented to the emergency department with a one-day history of left lower quadrant abdominal pain. A CT scan of abdomen and pelvis demonstrated acute diverticulitis, and incidentally a 6.2-cm heterogeneously enhancing exophytic mass along the inferior margin of the gastric body was seen. In addition, two lesions measuring 3.4 cm and 1.1 cm were seen adjacent to the gastrohepatic ligament (Figure 1). The patient’s abdominal pain improved with intravenous antibiotics. Gastroenterology was consulted given the mass lesions, and an endoscopic ultrasound was performed which showed three distinct heterogeneously hypoechoic masses (Figure 2), and fine needle biopsy (FNB) was performed. All three lesions were biopsied using three separate needles to avoid cross-contamination. Pathology of all three lesions was consistent gastrointestinal stromal tumor (GIST). Immunohistochemical staining was positive for DOG1 (Figure 3). The patient has been established with medical oncology for neoadjuvant therapy with Imatinib. DISCUSSION: Many GISTs are incidentally discovered on imaging or endoscopy. They are more frequently associated with early satiety, bloating, and bleeding although larger tumors can cause pain and symptoms of obstruction. Multifocal GISTs are exceedingly rare, other than exceptions in pediatric population, metastatic spread and hereditary syndromes. Newer studies suggest patients with multifocal GISTs may actually have multiple primary GISTs rather than metastatic spread, and molecular characterization can allow for proper staging and treatment planning. Multifocal GISTs have also been reported in patients with neurofibromatosis (NF) type I. However, our patient did not have any symptoms or signs suggestive of NF. It is important for gastroenterologists to know that multifocal GISTs can present in adults, and if suspicion is high, all lesions should be evaluated individually, and smaller lesions should not be attributed to metastasis unless proven otherwise.

2519 A Rare Case of Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma Involving Duodenum

INTRODUCTION: Primary small bowel lymphomas account for only 8-9% primary gastrointestinal malignancies and mostly represent extra nodal B- or T-cell origin. Immunoproliferative small bowel disease (IPSID) is a common small bowel extra nodal primary lymphoma. Associated Lymphoid Tissue B cell lymphoma (MALT lymphoma) is a common primary gastric lymphoma. However, it is very rare to find MALT lymphoma in small bowel especially in duodenum. We report a unique case of MALT lymphoma involving duodenal bulb. CASE DESCRIPTION/METHODS: A 58-Yr-Old African American female, with history of type II diabetes, Hypertension, Osteoarthritis, and chronic GERD with symptom control on once a day low dose omeprazole was referred for evaluation of epigastric discomfort, bloating, and nausea for 2 months. Abdominal examination normal. Labs showed normal CBC with differential, and CMP. An upper endoscopy showed mild patchy erythema in stomach and a localized, raised, and nodular area about 4-5 cm in the duodenal bulb. Biopsies from stomach showed Helicobacter pylori chronic active gastritis. Biopsies from duodenum showed homogenous population of lymphoid cells with moderate amounts of clear cytoplasm expanding the lamina propria. Molecular studies showed positive B-cell Gene Rearrangement with positive Framework 1, 2, and 3. Immunohistochemical staining was positive for CD20, bcl2, and kappa; and negative for CD3, CD5, CD10, bcl6, CD43, Cyclin D1 and lamda. The pathology findings confirmed Margina zone lymphoma of Mucosa Associated Lymphoid Tissue (MALT lymphoma). Colonoscopy was normal except few diverticula. A CT scan of abdomen, pelvis, and chest did not show any other masses except prominent lymph nodes at the gastrohepatic ligament and duodenum. She is treated with antibiotic therapy for H pylori gastritis, and referred to oncology for further management. DISCUSSION: MALT lymphomas of stomach usually occur in females and can be associated with Helicobacter pylori infection. They are usually low grade lymphomas and localized to gastrointestinal epithelium. Clinical features, imaging, or endoscopy findings are not specific. Immunohistochemical staining shows positive for B cell phenotype markers like CD20, Bcl-2, and negative for CD 23, CD 10, and CD 5. Usually, they present with non-specific symptoms like epigastric pain, nausea, vomiting, early satiety, though can present with obstruction when the tumor is too large. Treatment of associated H pylori infection may help though chemoradiotherapy may be needed rarely.

1663 Do Not Risk Your Colon: Beware of Hydrogen Peroxide Enema

INTRODUCTION: Hydrogen peroxide is an oxidizing agent widely available in a variety of medical and household products. There are few reported cases of chemical colitis due to hydrogen peroxide enema used for constipation. We present an interesting case of chemical colitis due to hydrogen peroxide enema used by the patient for alcohol detoxification after reading on the internet. CASE DESCRIPTION/METHODS: A 33-year-old male with a history of alcohol abuse presented with complains of abdominal pain and hematochezia that started after self-administration of enema with 3% hydrogen peroxide diluted with saline for alcohol detoxification. On the abdominal exam, he had left lower quadrant tenderness. Vital signs were stable. CBC revealed mild anemia with hemoglobin (Hb) of 13 g/dl while BMP was unremarkable. CT scan of abdomen and pelvis showed mucosal thickening, edema and subtle pericolonic stranding changes of the rectosigmoid colon to proximal descending colon and no free air. Gastroenterology was consulted and the patient underwent flexible sigmoidoscopy which showed diffuse moderate inflammation in the rectum, sigmoid colon, descending colon and splenic flexure secondary to colitis. The patient was managed conservatively with bowel rest, fluid resuscitation and empiric antibiotics. Hemoglobin remained stable and he was discharged once he was able to tolerate diet and his symptoms resolved. DISCUSSION: Chemical colitis is the inflammation of the large intestine caused due to chemicals introduced into the colon after accidental contamination of endoscopes or administration of enemas containing various chemicals like hydrogen peroxide. Hydrogen peroxide produces highly reactive oxygen radicals which damages colonic mucosa. Diagnosis can be challenging if pertinent history is not obtained as patients with chemical colitis present with non-specific GI symptoms that mimic inflammatory colitis. Given readily availability of hydrogen peroxide and information on the internet to the public, patients should be educated about the dangers of hydrogen peroxide enema. Physicians should also be aware of these dangerous and life threatening ways their patients can attempt to relieve constipation or detoxification. It is very important to recognize this entity as it is entirely preventable.

1483 Full Thickness Resection Device for the Removal of a Submucosal Sigmoid Carcinoid Tumor

INTRODUCTION: Colonic neuroendocrine tumors (NETs) are rare neoplasms, but they carry the worse prognosis. Management of these tumors is difficult and may result in repeated interventions and prolonged surveillance. Endoscopic Full Thickness Resection (FTR) is not currently included in the guidelines for management of NETs. This case describes a technically and histologically successful FTR of a sigmoid goblet cell carcinoid tumor. CASE DESCRIPTION/METHODS: A 61-year-old male presents for screening colonoscopy and was found to have an 8 mm submucosal mass in the distal sigmoid. Pathology of biopsies showed hyperplastic colonic mucosa with marked reparative stromal and epithelial changes and mixed features of prolapse. He was referred to our institution for EUS of the submucosal lesion, which revealed hypoechoic submucosal lesion in distal sigmoid measuring 7.4 × 4.7 mm. FNA was attempted but unsuccessful as the mass was small and mobile. Therefore, decision was made to perform endoscopic mucosal resection (EMR). Pathology on EMR of sigmoid lesion revealed goblet cell carcinoma. Deep and lateral margins were positive. Chromogranin A level was mildly elevated. He was referred to surgical oncology who recommended 3 month surveillance colonoscopy given low Ki index. CT Scan of Abdomen and Pelvis as well as Octreotide scan were both negative for distant metastases. At 3-month follow up colonoscopy, the decision was made to use Full Thickness Resection Device (FTRD) of the sigmoid lesion given positive margins. Pathology of FTRD was consistent with neural sheath tumor and deep and lateral margins were negative. Repeat colonoscopy revealed well healed scar at site of FTRD and cold biopsies around the scar were benign. He will follow up in 3 years for repeat colonoscopy. DISCUSSION: Primary colonic neuroendocrine tumors are rare but are generally more aggressive and carry the worst prognosis dependent on stage. Current consensus guidelines for the management of local regional NETs recommend endoscopic resection via polypectomy, EMR or endoscopic submucosal dissection. There have only been a few reported cases of the use of FTRD to treat submucosal carcinoid tumors in the colon. Success rates for endoscopic full thickness resection of gastric tumors has been described in the literature with success rates of up to 100%. High success rates of FTRD on colorectal lesions, not NETs, have also been noted. Given this, FTRD should be considered as a more definitive modality for treatment involving submucosal carcinoid tumors.

3223 Knot in the Stomach: Metastatic DLBCL Disguised as an Ulcer

INTRODUCTION: Early primary gastrointestinal non-Hodgkin's lymphomas can be difficult to diagnose and can be mistaken for diseases such as Crohn's disease or intestinal tuberculosis. We present a 73-year-old patient who had large duodenal bulb ulcer on endoscopy that resulted in metastatic DLBCL. CASE DESCRIPTION/METHODS: A 73-year-old female with history of osteoporosis, Vitamin B12 deficiency, and leukopenia presented to her primary care physician complaining of feeling knot in upper abdomen for 1 month. She felt the knot was getting progressively bigger with mild abdominal discomfort. She had also complained of early satiety, abdominal bloating, and weight loss of 3-4 pounds in past few months. She denied diarrhea or blood in the stools. Physical exam was significant for minimal distension with prominent palpable pass in right upper abdomen with tenderness to palpation and no lymphadenopathy. Labs showed WBC 4.0, Hb 11.6, Plt 417, Alkaline Phosphatase 235, Alb 3.3. CT scan of abdomen pelvis showed circumferential mass like thickening along gastric antrum, mesenteric implants, and periaortic lymphadenopathy concerning for gastric carcinoma or lymphoma. She was referred to oncologist and gastroenterologist for evaluation with upper endoscopy. EGD showed large duodenal bulb ulcer with necrotic base and small ulcer in antrum. Duodenal biopsy showed newly diagnosed stage IV Diffuse Large B-Cell Lymphoma that also involved gastric, gallbladder, and pancreas. She completed 3 cycles of R-CHOP chemotherapy and was started on high-dose methotrexate for CNS prophylaxis. She had Whipple procedure done after leak of gastrografin and noted to have perforated duodenum. DISCUSSION: Diagnosis of primary GI lymphoma is difficult as it can be nonspecific and often benign gross appearance on endoscopy or colonoscopy. The duodenum represents roughly 6-8% of sites involving small intestine lymphoma. DLBCL of the intestine treated with surgery plus CHOP or R-CHOP chemotherapy has very good prognosis. Early diagnosis and treatment is crucial due to the aggressive nature of this malignancy.

3037 Spontaneous Cystgastrostomy From Pancreatic Pseudocyst Erosion Into Gastric Wall Resulting in Gastrointestinal Hemorrhage

INTRODUCTION: Pancreatic pseudocysts are a common complication of pancreatitis. Spontaneous erosion of a pseudocyst into adjacent organs is rare, manifesting in a variety of clinical symptoms and presentations. We present a case of spontaneous fistulization of a pancreatic pseudocyst into the stomach resulting in life-threatening bleeding. CASE DESCRIPTION/METHODS: A 60-year-old gentleman with history of type 2 diabetes mellitus, hypertension and chronic pancreatitis with known pancreatic pseudocyst presented with multiple episodes of melena associated with fatigue, weakness and epigastric pain aggravated by food intake. He denied history of peptic ulcer disease but admitted to chronic NSAID use. Physical examination revealed a pale patient with mild generalized abdominal tenderness without signs of peritonitis. Melenic stools were noted on digital rectal exam. Labs were significant for critical normocytic anemia with Hgb 6.3 g/dL. CT scan of abdomen and pelvis showed an 11.7 × 9 cm lesion in the pancreatic body with calcified rim communicating with gastric antrum. Gastrograffin swallow showed contrast transfer from stomach into the pseudocyst. A CT-Angiogram of the abdomen and pelvis failed to reveal a source of bleeding or peripancreatic pseudoaneurysms. Patient underwent EGD which showed 1 centimeter antral fistula-opening representing a spontaneous cystogastric fistula. No ulcers were found. The patient eventually underwent surgical excision of pancreatic pseudocyst, antrectomy and Billroth-II reconstruction. DISCUSSION: Pseudocysts complicate 20-40% of chronic pancreatitis. They can cause pain, bowel obstruction, infection, or hemorrhage. Treatment is indicated when cysts become symptomatic or grow beyond 5 cm. However, pseudocysts often resolve by spontaneous drainage into the pancreatic ductal system. Rarely, they can rupture into the peritoneal cavity or erode into nearby hollow organs. Bleeding can be the result of pseudocyst erosion into nearby vessels or rupture of nearby pseudoaneurysms. While involvement of gastroduodenal, splenic, hepatic and inferior pancreaticoduodenal arteries has been reported, none of these sources could be identified in this case. Treatment can take the form of direct embolization or surgical hemostasis. In summary, we have presented a case of pancreatic pseudocyst with spontaneous cystogastric fistula formation accompanied by massive upper GI bleeding eventually treated by surgical excision and Billroth-II reconstruction.

Morphometric measurement and applicable feature analysis of sacral alar-iliac screw fixation using forward engineering.

To evaluate S1AI-S4AI screw channels with three-dimensional digital technology simulation analysis and to study the feasibility and applicable features of sacral alar-iliac screw fixation in adults. Forty (20 men and 20 women) normal adult's pelvic CT scan data sets were selected to reconstruct the three-dimensional pelvic model. The ideal S1AI-S4AI screw channels were simulated, followed by precise measurement of their parameters. The results showed that there were no significant differences in the transverse angles, sagittal angles, radiuses of the maximal inscribed circles, or lengths of the screw channels in S1AI-S2AI screws between genders (P > 0.05). In contrast, the radiuses of the maximal inscribed circles on the left and right, respectively, were 5.93 ± 1.02mm and 5.92 ± 1.04mm in males and 4.64 ± 0.98mm and 4.59 ± 0.95mm in females, and there was a significant difference in S3AI screws between genders (P < 0.05). With a radius of 2.50mm considered to be standard, there were 25 cases (62.5%) with an S4AI screw channel radius ≤ 2.50mm in 40 adults, and 15 cases (37.5%; 9 males and 6 females) with a radius > 2.50mm. Furthermore, the transverse angles, the sagittal angles, the lengths of the screw channels, and the radiuses of the maximal inscribed circles were significantly different between genders in 15 cases (P < 0.05). Only one maximum ideal screw can be placed on one side at a time. With a radius of 2.50mm considered to be standard, it is feasible to place S1AI-S3AI screws with a radius > 2.50mm in the entire adult population and S4AI screws with a radius > 2.50mm in some of the adult population. Furthermore, preoperative three-dimensional reconstruction and three-matic research software can effectively simulate the sacral alar-iliac screw channels, and they can provide accurate data for clinical applications.