Ampullary and Pancreatic Neuroendocrine Tumors: A Series of Cases and Review of the Literature

Incidental Finding of a Periampullary Neuroendocrine Tumor: A Case Report

A 63-year-old male with multiple co-morbidities presented with a diabetic foot infection which was treated surgically. During admission to the hospital, he developed melena and underwent an endoscopic assessment which revealed an incidental finding of an ampullary mass. The histological analysis of the biopsy revealed ampullary carcinoma with mixed intestinal-type and pancreatobiliary-type features. A magnetic resonance imaging (MRI) of the liver with contrast presented the tumor as an ill-defined small soft tissue lesion measuring 8 x 9 mm in the ampullary region, with multiple lymph nodes in the periportal, peripancreatic, and para-aortic regions. There was no evidence of biliary obstruction. The patient underwent a Whipple procedure with no complications. The final histology report of the specimens taken stated that the tumor is predominantly in the duodenum and focally in the ampulla, and is a well-differentiated neuroendocrine tumor confirmed to be submucosal. The histopathologic and radiologic workup determined the pathological stage classification to be pT3N1, Mx G1.

Ampullary Large-Cell Neuroendocrine Carcinoma, a Diagnostic Challenge of a Rare Aggressive Neoplasm: A Case Report and Literature Review

Ampullary large-cell neuroendocrine carcinomas (LCNECs) are extremely rare, and available data are limited on case reports. They present with jaundice, non-specific abdominal pain, or weight loss, imitating adenocarcinoma. Their incidence increases due to the improved diagnostic techniques. However, preoperative diagnosis remains challenging. We report the case of a 70-year-old man with a history of metabolic syndrome, cholecystectomy, and right hemicolectomy, presenting with jaundice. Laboratory results showed increased liver biochemistry indicators and elevated CA 19-9. Esophagogastroduodenoscopy revealed an ulcerative tumor on the ampulla of Vater, and the biopsy revealed neuroendocrine carcinoma. Although computed tomography (CT) detected enlarged regional lymph nodes, the positron emission tomography (PET) showed a hyperactive lesion only in this area. Pylorus-preserving pancreatoduodenectomy with R0 resection was performed. Pathologic evaluation of the 3.1 × 1.9 cm tumor revealed an LCNEC with immunohistochemical positivity at Synaptophysin, EMA, CD56, and cytokeratin CK8/18. The Ki-67 index was 45%. Two out of the nine dissected lymph nodes were occupied by the neoplasm. The patient was discharged home free of symptoms, and adjuvant chemotherapy with carboplatin + etoposide was initiated. A comprehensive review of the reported cases showed that the preoperative biopsy result was different from the final diagnosis in few cases, regarding the subtypes. Conventional radiology cannot identify small masses, and other methods, such as endoscopy, magnetic resonance cholangiopancreatography (MRCP), and FDG-PET scan, might aid the diagnosis. Diagnosis is based on histology and immunohistochemical markers of the surgical specimens. The treatment of choice is pancreatoduodenectomy, followed by adjuvant chemotherapy. However, recurrence is frequent, and the prognosis remains poor.