A barium enema in a 60-year-old man shows an 'apple-core' or 'napkin ring' filling defect with shouldering at the margins in the sigmoid colon. The mucosa within this segment is destroyed. What is the most likely diagnosis?
- A Annular carcinoma of the colon ✓
- B Crohn's disease
- C Diverticular stricture
- D Extrinsic compression by pelvic mass
Correct answer: A. Annular carcinoma of the colon
Explanation
An annular (circumferential) carcinoma of the colon produces the classic 'apple-core' or 'napkin ring' appearance on barium enema, with abrupt shouldered margins, mucosal destruction, and irregular luminal narrowing over a short segment. This pattern distinguishes malignancy from Crohn's disease, which shows a longer segment with mucosal cobblestoning and skip lesions. Diverticular strictures are associated with diverticula elsewhere and show preserved mucosa. Extrinsic compression displaces rather than destroys the mucosa.
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.