Brett C. Sklaw

An Interesting Cause of Rectal Bleeding in an African Immigrant

Question: A 30-year-old Sudanese-born man who emigrated to the United States 10 years ago with a past medical history of hepatitis B as well as recently treated Helicobacter pylori gastritis presented for outpatient follow-up for management of hepatitis B. His previous symptoms of heartburn and dyspepsia had improved with treatment of H pylori. He now complained of rectal bleeding with anal pruritus. He had no recent travel, no sick contacts, and had not started any new medications. On physical examination, he was afebrile with stable vital signs. He seemed well nourished. He had no scleral icterus. His abdominal examination was benign. He had no rash or jaundice. Rectal examination revealed no abnormalities. Complete blood count with differential revealed a white blood count of 3.1 K/ L with 6.1% eosinophils. Chemistry was normal. Liver function tests were unremarkable other than a stable total bilirubin of 1.8 g/dL. A flexible sigmoidoscopy (Figure A) was performed which revealed erythematous mucosa in the sigmoid colon, which was biopsied for pathologic examination (Figure B and C). What is the diagnosis? How should this patient be treated? See the GASTROENTEROLOGY web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI.

Tu1912 Determining Novel Clinicopathologic Correlations of High Grade Pancreatic Intraepithelial Neoplasia (PanIN) in Pancreatic Ductal Adenocarcinoma (PDAC)

Background: Pancreatic cancer has an extremely poor prognosis. At the time of diagnosis, over 80% of patients have locally advanced or invasive disease. The carcinogenesis of pancreatic ductal adenocarcinoma (PDAC) involves stepwise progression from pancreatic intraepithelial neoplasia (PanIN) to invasive carcinoma. PanINs measure less than 5 mm and are not detectable on current imaging modalities. Precursor lesions, such as high-grade PanIN (PanIN-3) represent a target for early intervention. Low grade PanIN-1 and -2 are widely prevalent but their significance is unclear. Aims: To evaluate prevalence, significance and implications of PanIN-3 in PDAC. Methods: A retrospective review of the pathology database (1/2000 to 7/2013) at a tertiary care center. Demographic information, patient history, imaging studies, EUS findings and surgical pathology were reviewed. Results: A total of 607 pancreatic resections for cystic and solid lesions were reviewed. Neoadjuvant chemotherapy was given to 48 patients. In the remaining 559 patients, 198 (35.4%) had primary surgical resection for PDAC. Among these patients, 74.5% (of 185) showed the presence of any subtype of PanIN. High grade or PanIN-3 was present in 36.2% (of 185) resections for PDAC. Further, PanIN-3 was mostly found in PDAC (90.5%, p-value <0.001) compared to all other lesion types. Among patients with PDACs, who did not receive neoadjuvant therapy, univariate analysis (tables 1 and 2), demonstrated that Caucasian race and the presence of perineural invasion were significantly associated with PanIN-3. Pathological evidence of chronic pancreatitis and higher number of positive lymph nodes trended towards significant. Using these variables in a binomial logistic regression model demonstrated that Caucasian race (OR 10.9, p-value 0.02, 95% confidence interval 1.4, 86.6) and the presence of perineural invasion (OR 6.4, p-value 0.02, 95% confidence interval 1.4, 29.2) were significantly associated with PanIN-3. Interestingly, a comparison of PanIN3 among PDACs who underwent primary surgical resection versus post-neoadjuvant chemotherapy resection revealed that there was an absence of significant reduction in PanIN-3 among post-neoadjuvant resected PDACs (66 of 168 (39.3%) vs. 12 of 36 (33.3%), p = 0.57). Conclusion: High grade PanIN lesions are particularly prevalent in PDACs. In patients undergoing primary surgical resection for PDACs, high grade PanIN-3 lesions were notably associated with Caucasian race and perineural invasion. Supporting prior literature that PanIN-3 lesions may harbor cells with invasive features, the finding of PanIN-3 association with perineural invasion needs to be validated by larger studies. Table 1. Univariate analysis of clinicopathologic categorical variables of PanIN-1 and -2 vs. PanIN-3

Tu1301 Predictors of Severe Dysplasia in Surgically Resected Non-Malignant Intraductal Papillary Mucinous Neoplasms (IPMN)

Background & Aims: Endoscopic ultrasound (EUS) is often used as the gold standard to diagnose chronic pancreatitis (CP) despite concerns about its intra-operator reliability and validity. We sought to determine the benefit of repeat EUS in patients suspected of having CP but having an equivocal or negative initial EUS exam for CP. Methods: Patients who underwent at least two EUS exams at our medical center to evaluate for CP from 20012012 were identified. Demographic, procedural and etiologic factors were abstracted via chart review. Specifically, EUS minimal standard criteria (MST) for CP (hyperechoic foci, hyperechoic strands, lobularity, cysts, ectatic duct, hyperechoic ductal wall, dilated side branches, ductal stones, ductal dilation) were abstracted for all exams. Diagnosis of CP was based on physician impression following each EUS. Results: Between the first and second EUS exams, the number of patients diagnosed with CP increased from 49% to 76% (p<0.01). Additionally, the number of patients with an indeterminate diagnosis after the first exam decreased significantly after the second exam (41% vs 21%, p<0.01). The presence of hyperechoic foci increased on the second exam (50% vs. 68%, p=0.04), but no other parenchymal or duct features were found to reliably increase. On subgroup analysis, significant increases in hyperechoic foci identified on repeat EUS were found in women (43% vs 67%, p=0.03), patients under the age of 50 (47% vs 74%, p<0.02) and patients in whom recurrent acute pancreatitis is the etiology of their CP (18% vs 73%, p=0.03). Conclusions: Serial EUS exams are valuable in patients with indeterminate prior EUS exams in whom the diagnosis of CP is not secure. In particular, women and those <50 years old appear to benefit the most from serial evaluation.

Tu1303 Risk of Adenocarcinoma in Resected Intraductal Papillary Mucinous Neoplasm (IPMN) With Involvement of the Main Pancreatic Duct (MD)

Background & Aims: Endoscopic ultrasound (EUS) is often used as the gold standard to diagnose chronic pancreatitis (CP) despite concerns about its intra-operator reliability and validity. We sought to determine the benefit of repeat EUS in patients suspected of having CP but having an equivocal or negative initial EUS exam for CP. Methods: Patients who underwent at least two EUS exams at our medical center to evaluate for CP from 20012012 were identified. Demographic, procedural and etiologic factors were abstracted via chart review. Specifically, EUS minimal standard criteria (MST) for CP (hyperechoic foci, hyperechoic strands, lobularity, cysts, ectatic duct, hyperechoic ductal wall, dilated side branches, ductal stones, ductal dilation) were abstracted for all exams. Diagnosis of CP was based on physician impression following each EUS. Results: Between the first and second EUS exams, the number of patients diagnosed with CP increased from 49% to 76% (p<0.01). Additionally, the number of patients with an indeterminate diagnosis after the first exam decreased significantly after the second exam (41% vs 21%, p<0.01). The presence of hyperechoic foci increased on the second exam (50% vs. 68%, p=0.04), but no other parenchymal or duct features were found to reliably increase. On subgroup analysis, significant increases in hyperechoic foci identified on repeat EUS were found in women (43% vs 67%, p=0.03), patients under the age of 50 (47% vs 74%, p<0.02) and patients in whom recurrent acute pancreatitis is the etiology of their CP (18% vs 73%, p=0.03). Conclusions: Serial EUS exams are valuable in patients with indeterminate prior EUS exams in whom the diagnosis of CP is not secure. In particular, women and those <50 years old appear to benefit the most from serial evaluation.