A case of alpha-fetoprotein-producing acinar cell pancreatic carcinoma of which was indistinguishable from gastric cancer

Abstract

A 63-year-old man developed tarry stools. On upper gastrointestinal endoscopy, a reddish lesion was found in the middle body of the stomach. Based on the pathology of the biopsy specimen, a diagnosis of adenocarcinoma was made. On laboratory testing, a slight anemia and a high serum alpha-fetoprotein (AFP) level (871.1 ng/ml) were noted. On abdominal computed tomography, a large mass, 10 cm in diameter, was seen in the left upper abdomen ; there was invasion of the stomach, pancreatic tail, and spleen. Though the tumor was heterogeneously enhanced by iopamidol, the central part of the tumor showed no enhancement. An adenocarcinoma originating from the stomach or pancreas was diagnosed. The patient had a left upper abdominal exenteration. On gross examination, the tumor had a lobulated pattern and was not encapsulated. On histology, tumor cells with acinar and tubular structures were found ; the whole layer of the stomach was replaced by the infiltrating tumor cells. The tumor cells were positive on anti-trypsin mAbs immunohistochemical staining. The final histological diagnosis was acinar cell carcinoma of the pancreas. Postoperatively, the patient's AFP level normalized, and no signs of recurrence have been seen on follow-up.