Abstract
We report a rare male case of an undifferentiated carcinoma with osteoclast-like giant cells originating in an indeterminate mucin-producing cystic neoplasm of the pancreas. A 59-year-old Japanese man with diabetes visited our hospital, complaining of fullness in the upper abdomen. A laboratory analysis revealed anemia (Hemoglobin; 9.7 g/dl) and elevated C-reactive protein (3.01 mg/dl). Carbohydrate antigen 19-9 was 274 U/ml and Carcinoembryonic antigen was 29.6 ng/ml. A computed tomography scan of the abdomen revealed a 14-cm cystic mass in the upper left quadrant of the abdomen that appeared to originate from the pancreatic tail. The patient underwent distal pancreatectomy/splenectomy/total gastrectomy/cholecystectomy. The mass consisted of a multilocular cystic lesion. Microscopically, the cyst was lined by cuboidal or columnar epithelium, including mucinous epithelium. Sarcomatous mononuclear cells and multinucleated osteoclast-like giant cells were found in the stroma. Ovarian-type stroma was not seen. We made a diagnosis of osteoclast-like giant cell tumor originating in an indeterminate mucin-producing cystic neoplasm of the pancreas. All surgical margins were negative, however, two peripancreatic lymph nodes were positive. The patient recovered uneventfully. Two months after the operation, multiple metastases occurred in the liver. He died 4 months after the operation.