LAUSR

Epidermoid cyst in the intrapancreatic accessory spleen (ECIAS) is an exceedingly rare nonneoplastic entity. It generally does not require therapeutic intervention, but it is often misdiagnosed preoperatively as a cystic tumor, such as a mucinous cystic neoplasm or a cystic degeneration in a solid pancreatic neuroendocrine tumor or solid pseudopapillary neoplasm. We herein report a rare case of ECIAS in a 33-year-old African American man with a history of end-stage renal disease secondary to IgA nephropathy, congestive heart failure, and sickle cell trait who was referred to our facility for a renal transplant workup. A contrast-enhanced abdominal computed tomography during the workup revealed a bilobed low attenuating mass (3.4 × 3.4 × 2.5 cm) in the tail of the pancreas. Because malignancy could not be excluded, the patient underwent a distal pancreatectomy and splenectomy. Gross examination of the surgical specimen revealed a smooth-walled, multiloculated cyst (3.7 × 2.7 × 2.0 cm), containing serous fluid within the pancreatic parenchyma. Microscopically, the cyst was lined by nonkeratinizing stratified squamous epithelium without skin appendages, surrounded by benign splenic tissue in the pancreatic parenchyma. No dysplasia or malignancy was seen. Immunohistochemically, the lining epithelium was positive for p63, CK5/6, and CEA and negative for CA19-9, which supports the above diagnosis. The postoperative course was uneventful. In conclusion, ECIAS is a rare benign entity that can mimic malignant conditions and should be considered in the differential diagnosis of cystic lesions in the tail of pancreas.