Incidental Enterogenous Cyst of the Pancreas: Resection or Observation?

Introduction: Enterogenous cysts of the pancreas are rare congenital foregut cysts. The natural history of these entities is still relatively unknown, as is their propensity for malignant transformation. Thus, optimal management is still undetermined. Case Description: A 39-year-old African American woman underwent a computed tomography scan of the chest that showed an incidental cystic lesion of the pancreas. Endoscopic ultrasonography–guided fine-needle aspiration (FNA) identified an elevated carcinoembryonic antigen level, as well as benign, focally ciliated columnar cells, histiocytes, and proteinaceous material, with no evidence of malignant transformation. These findings were consistent with respiratory or bronchial versus dermoid or endometrial (müllerian) origin. A laparoscopic distal pancreatectomy was performed, and the final pathologic findings showed gastric tissue surrounded by a rim of normal pancreatic tissue, consistent with a benign enterogenous cyst. The patient recovered well. Discussion: Enterogenous cysts that arise outside of the liver are exceedingly rare and represent both a diagnostic and therapeutic challenge. On imaging, they can be mistaken for malignant cystic lesions. Pathologic examination provides definitive identification, with FNA smears giving pathognomonic characteristics; however, FNA samples can miss the architecture of the cyst. Moreover, there is limited knowledge of the natural history of these lesions, and reports exist of other enterogenous or developmental abnormalities undergoing malignant transformation. Although it would be preferential to avoid unnecessary surgery for these rare lesions, not enough is known about their behavior. Surgery remains the standard of care and the more “conservative” management option for these cystic lesions of the pancreas.