Retroperitoneal Congenital Epidermoid Cyst Misdiagnosed As a Solid Pseudopapillary Tumor of the Pancreas: A Case Report

Background: Retroperitoneal cysts are rare and usually asymptomatic abdominal lesions. Epidermoid cysts are frequent benign cutaneous tumors, but retroperitoneal localization of these cysts does not occur very often.

Case Summary: We report a case report of a 25-year-old woman with a giant mass in the abdominal cavity. Because imaging examination indicated that the mass probably originated from the pancreas, the mass was considered a solid pseudopapillary tumor of the pancreas (SPTP). However, surgery revealed a retroperitoneal epidermoid cyst located behind the pancreas neck and the root of the superior mesenteric artery (SMA). We performed complete resection of the tumor. Postoperative pathology showed an epidermoid cyst. The patient fared well after two months of follow-up.

Conclusion: Surgery is the gold standard for the diagnosis and treatment of retroperitoneal epidermoid cysts. Retroperitoneal epidermoid cysts around the pancreas are easily misdiagnosed as cystic SPTPs. Surgeons should pay particular attention to preoperative diagnosis to reduce severe surgical complications and improve the quality of life of patients.