A Rare Case of Epidermoid Cyst in the Pancreatic Tail Invaginated from the Splenic Hilum: The Long-term Changes in the Imaging Findings

Epidermoid cysts arising from both the pancreas and spleen are rare. We herein report a case of a surgically resected epidermoid cyst in the pancreatic tail invaginated from the spleen. A multi-locular cyst, 2 cm in diameter, without a solid component was discovered incidentally in the pancreatic tail. During the 11-year follow-up, the emergence of satellite cystic lesions with distinct appearances was seen, and surgical resection was selected despite the lack of any associated symptoms or evidence of cytological abnormalities. Histologically, these cysts were lined with benign multi-layered flattened epithelium surrounded by a thin layer consisting of cells positive for CD8 and CD68 and connecting to the spleen.