Adenoendocrine carcinoma of the accessory papilla of the duodenum: Report of a case

This report describes a very rare case of an adenoendocrine carcinoma of the accessory papilla of the duodenum. A 70-year-old woman was admitted to the hospital complaining of epigastralgia. Gastrointestinal endoscopy showed a protruding tumor with ulceration at the accessory papilla of the duodenum. A biopsy revealed a small-cell carcinoma. Computed tomography showed a highly enhanced tumor in the early phase. No metastatic lesions were shown. Magnetic resonance cholangiopancreatography showed dilatation of the pancreatic duct, but a normal common bile duct. A pyloruspreserving pancreaticoduodenectomy was performed with lymph node dissection. Microscopically, the tumor was a small-cell neuroendocrine carcinoma with adenomatous differentiation. An immunohistochemical analysis showed positive staining for synaptophysin, chromogranin A, CD56, and carbohydrate antigen 19-9. The final diagnosis was an adenoendocrine carcinoma with lymph node metastasis. The postoperative course was uneventful and the patient is now doing well as an outpatient after 14 months of follow-up.