Small solid pseudopapillary tumor of the pancreas in a 32-year-old man: report of a case.

A solid pseudopapillary tumor (SPT) of the pancreas is a rare neoplasm that mainly occurs in young women. We herein report the case of a small SPT arising from the head of the pancreas in an asymptomatic 32-year-old man, plus a literature review of this tumor. A 32-year-old man was admitted to our department at Kumamoto University Hospital for the evaluation of a pancreatic mass. The tumor had central necrosis, which was poorly perfused on contrast-enhanced computed tomography (CT) and which had a high intensity on T2-weighted magnetic resonance imaging (MRI). Histology revealed the lesion to be a solid pseudopapillary tumor of the pancreas, with the characteristic pseudopapilla formation and central degeneration. However, no capsule formation was observed. The tumor was positive for CD56, CD10, alpha1-antitrypsin, alpha1-antichymotrypsin, beta-catenin, and progesterone receptor. However, the tumor was negative for pancreatic hormones, chromogranin-A, carcinoembryonic antigen, and carbohydrate antigen 19-9. We diagnosed the patient to have an SPT based on these histological findings. Small-sized solid pseudopapillary tumors of the pancreas are being increasingly recognized because of the recent advances in CT and MRI. We should also consider SPT even if it occurs in a male when the tumor contains necrosis-suspected areas which are poorly perfused on contrast-enhanced CT with a high intensity on T2-weighted MRI.