Malignant papillary cystic tumor of the pancreas: report of a case and review of the literature.

Papillary cystic tumor of the pancreas almost always occurs in young female patient and metastasis is extremely rare although local recurrence may occur. Prognosis is excellent and the tumor can be considered to be curable by surgery. Reported here is an unusual case of malignant papillary cystic tumor of the pancreas that occurred in a 51 Y/O man with metastasis to bilateral inguinal soft tissue at the time of diagnosis. Beside distal pancreatectomy, subtotal gastrectomy and excision of the inguinal masses were also performed because of the presence of a separate tumor in the lesser sac, which was unrelated to the pancreas. Immunohistochemical staining for NSE was positive in tumor cells. However, electron microscopy failed to reveal neurosecretory or zymogen granules but there were abundant mitochondria, rough endoplasmic reticulum and annulate lamellae. These findings show that a ductal origin is more likely in our case but the hypothesis of an origin from a primitive cell capable of acinar, ductal or endocrine differentiation should also be considered.