Six weeks after recovering from severe acute pancreatitis, a 45-year-old alcoholic man has persistent upper abdominal discomfort and a palpable epigastric mass. CT shows a 6 cm well-defined cystic lesion adjacent to the pancreas. Aspiration reveals fluid rich in amylase. The single feature that definitively distinguishes this lesion from a cystic neoplasm of the pancreas is:

• A Presence of a thick fibrous wall
• B Elevated amylase content of the aspirated fluid
• C Location adjacent to the pancreas
• D Absence of an epithelial lining ✓

Explanation

A pancreatic pseudocyst is a collection of enzyme-rich fluid walled off by granulation tissue and fibrous reaction, and it lacks any epithelial lining, which is the defining distinction from true cysts and cystic neoplasms such as mucinous cystic neoplasm, which have a genuine epithelial layer. A fibrous wall, peripancreatic location and elevated fluid amylase can all occur in pseudocysts, but they do not by themselves exclude a neoplasm, so the absence of epithelium is the decisive feature.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.