Cruise, Michael W.

Patients with familial adenomatous polyposis (FAP) are at increased risk of developing cancer, with the most common sites being colorectal, duodenal/ampullary and thyroid. In the last decade, an alarming increase in gastric cancer has been reported in the Western FAP population. These cancers are often diagnosed at an advanced stage with poor prognosis, even in patients undergoing regular upper endoscopic surveillance. Most gastric cancers in Western patients with FAP occur in the proximal stomach, where a carpeting of fundic gland polyposis hampers visualization of gastric cancer and its precursor lesions during endoscopic surveillance. Although fundic gland polyps are the most prevalent proximal polyp, several different dysplastic lesions can be found in the stomachs of patients with FAP. including fundic gland polyps with dysplasia, foveolar-type adenomas, pyloric gland adenomas, and intestinal-type adenomas. Although adenomas are the most likely precursors to gastric cancer, the exact lesions responsible for gastric cancer in FAP are not yet fully understood. This review focuses on gastric polyposis and the characteristics of gastric cancer in Western patients with FAP, including risk factors, lesion detection, surveillance and management of gastric polyposis, and areas for future research.

AbstractBackgroundAutoimmune pancreatitis (AIP) is a known mimicker of pancreatic ductal adenocarcinoma both clinically and radiologically. In this study, the authors present their institutional experience in diagnosing AIP on cytology and correlate results with the histologic findings.MethodsA 14‐year computerized search for patients who had histologically confirmed AIP with concurrent or prior cytology was performed. Clinical data, cytology findings, and surgical pathology results were reviewed for analysis.ResultsEighteen patients were identified. The patients showed a male predominance, with a mean age of 59 years. Jaundice, weight loss, and abdominal pain were the most common clinical presentation. Five of 12 patients who were tested for serum immunoglobulin G4 had elevated levels. Cytologic findings of 16 cases that were available for review showed markedly inflamed fibrous stroma (54%) and cytologic atypia (50%). The final cytologic diagnoses were suspicious for adenocarcinoma (n = 1), atypical (n = 8), and benign/negative (n = 9). The corresponding surgical pathology diagnoses were classified as type 1 (n = 10), type 2 (n = 6), and AIP, not otherwise specified (n = 2). All type 2 AIP cases had at least atypical cytologic diagnoses, with one called suspicious for adenocarcinoma and another called adenocarcinoma at the time of rapid on‐site evaluation. In contrast, eight of 10 type 1 AIP cases were negative/benign, and two of 10 were atypical. In these two atypical cases, the possibility of AIP was raised because of the presence of inflamed stroma.ConclusionAIP is a pitfall in cytology because moderate‐to‐marked atypia can be present, especially in type 2 AIP. Because atypia can be severe, the presence of cellular fibrous stroma with lymphocytic stromal infiltrates and the integration of serum immunoglobulin G4 levels could be helpful in avoiding diagnostic overcall in AIP.