Endometriosis of the pancreas presenting as a cystic pancreatic neoplasm with possible metastasis

The authors report a case of endometriosis that presented as a cystic mass in the tail of the pancreas, leading to extensive evaluation and ultimately a major surgical resection. The diagnosis was made by histopathological evaluation, revealing endometrial glands and stroma in the wall of the mass with hemorrhagic fluid in the cystic lumen, compatible with pancreatic involvement by an endometrial cyst.