A 41-year-old alcoholic man, six weeks after an episode of severe acute necrotising pancreatitis, has persistent epigastric pain. Contrast-enhanced CT shows a well-defined collection in the lesser sac with a complete, smooth enhancing wall thicker than 2 mm. The contents are heterogeneous, with fat-density locules interspersed with pockets of fluid. According to the revised Atlanta classification, this collection is best termed:

• A Acute necrotising collection
• B Walled-off pancreatic necrosis ✓
• C Mature pancreatic pseudocyst
• D Infected pancreatic pseudocyst

Explanation

Beyond four weeks, a necrotising collection that becomes encapsulated by a well-defined enhancing wall is a walled-off necrosis. Its defining feature is heterogeneous content containing solid necrotic debris, often with fat-density locules. A mature pseudocyst also appears after four weeks but must contain homogeneous liquid content with no solid material, which is precisely what excludes option C here. An acute necrotising collection lacks an encapsulating wall entirely.

Reference: Sutton's Textbook of Radiology and Imaging, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.