Giant Cyst of Intrapancreatic Accessory Spleen Mimicking a Malignant Cystic Neoplasm of the Pancreas: A Case Report

Introduction: Epidermoid cyst in an intrapancreatic accessory spleen (ECIPAS) is an exceedingly rare pancreatic lesion that is always mistakenly suspected of malignancy preoperatively.

Case Summary: A 25-year-old male patient incidentally found a giant mass in the left upper abdomen neighboring the hilum of the spleen. The patient denied any obvious discomfort. Except for a slightly elevated carbohydrate antigen 19-9 (CA-19-9, 43.5 U/mL), no abnormal laboratory test results were found. Contrast-enhanced computed tomography, conventional ultrasound, and magnetic resonance imaging were performed. The patient received a laparoscopic distal pancreatectomy. The final pathology showed ECIPAS. The postoperative course was uneventful and no signs of recurrence during 2 years of follow-up.

Discussion: For an incidental pancreatic cystic lesion, ECIPAS should be considered in the differential diagnosis. ECIPAS may mimic pancreatic cystadenoma. Imaging follow-up or surgical removal may be useful for the exclusion of malignant risks in ECIPAS.