Gastrointestinal: Annular pancreas: duodenal ampulla cancer

We reported a 71-year-old female patient. The patient was hospitalized seven times for acute pancreatitis and with an abdominal magnetic resonance imaging (MRI) (Fig. 1a) and magnetic resonance cholangiopancreatography (MRCP) suggesting abnormalities in the anatomy of the pancreas, which was an annular pancreas (Fig. 1b). The patient has been admitted to the hospital again. Contrast enhanced CT examination suggested duodenal ampulla cancer (Fig. 1c,d). The patient underwent surgical resection as a curative procedure. (Fig. 2a). The hematoxylin–eosin staining (Fig. 2b) and immunohistochemistry pathology, CEA (Fig. 2c), Ki-67 (Fig. 2d), and CerbB-2 (Fig. 2e) were performed on the resected specimen. Based on the patient's contrast enhancing CT examination, duodenal ampulla adenocarcinoma was diagnosed. Ampulla cancer is a relatively common tumor. However, due to the abnormal anatomical structure of the pancreas, the formation of a circular pancreas led to repeated episodes of acute pancreatitis and finally led to the rare occurrence of malignant tumors in the ampulla. The annular pancreas is present in <1% of the population and originates from failed or abnormal migration/rotation of the ventral pancreatic bud. It is generally a congenital disease. Trisomy 21, duodenal atresia, and tracheoesophageal fistula may be associated with it.1 The annular pancreas is usually diagnosed during infancy with episodes of obstruction. In adults, it presents with acute/recurrent pancreatitis or peptic ulcer. We hope that the recognition of the abnormalities of pancreatic structure, recurrent acute pancreatitis leading to malignancy, will be brought to the attention of the patient in this case. The adult-type annular pancreas is a rare disease. Additionally, since the annular pancreas is associated with ampullary malignant tumors, periodic follow-ups should be made after a definite diagnosis of the asymptomatic annular pancreas so that ampullary malignant tumors can be surveyed and treated in time. It will also increase clinicians' understanding of the complications of the annular pancreas and provide a reference for future clinical treatment. Informed consent was obtained from the patient.