Malignant Transformation of an Epidermoid Cyst in an Intrapancreatic Accessory Spleen: A Case Report.

A 33-year-old man was evaluated because of an incidentally found cyst in the pancreatic tail, which was first seen 6 years ago. The cyst was a unilocular cystic mass, 13.0 cm in diameter, and had increased in size in last 2 months. On F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT), the cystic wall showed increased FDG uptake. The patient underwent distal pancreatectomy with suspicion of mucinous cystic neoplasm of the pancreas. The mass turned out to be a squamous carcinoma arising from an epidermoid cyst in an intrapancreatic accessory spleen (ECIPAS). FDG PET/CT may assist recognition of a potential malignant lesion arising from an ECIPAS.