title: Epidermoid cyst occurring within an intrapancreatic accessory spleen. A case report and review of the literature.
abstract: BACKGROUND
  Epidermoid cysts occurring within intrapancreatic accessory spleens are exceptionally rare entities, with only 21 previously reported cases. Their clinical presentation prior to pathologic assessment can raise concern for possible malignancy; however, they behave in a benign fashion.
  
  
  METHODS
  A 62-year-old male presented with complaints of abdominal pain. Imaging revealed left-sided retroperitoneal mass and surgical exploration was recommended. Surgery revealed a cystic cavity containing necrotic debris originating from the tail of the pancreas. Microscopy was consistent with an epidermoid cyst arising within an intrapancreatic accessory spleen with positive immunoperoxidase staining for CEA.
  
  
  CONCLUSIONS
  Epidermoid cysts occurring within intrapancreatic accessory spleens can mimic a malignant process both clinically and radiographically. Surgery with pathologic assessment is the only reliable means of diagnosis. While they are a very rare entity, it is an important component of a complete differential diagnosis for a patient presenting with a pancreatic tail mass.
authors.affiliation: Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA. ahor1@unmc.edu
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Horn
authors.forename: Subodh M
authors.initials: SM
authors.lastname: Lele
mesh_terms: D002272:Carcinoembryonic Antigen / Q000378:metabolism; D002828:Choristoma / Q000175:diagnosis* / Q000378:metabolism; D003937:Diagnosis, Differential; D004814:Epidermal Cyst / Q000175:diagnosis* / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D010182:Pancreatic Diseases / Q000175:diagnosis* / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000378:metabolism; D013154:Spleen
chemical_list: D002272:Carcinoembryonic Antigen