Distention of the appendix or colon with mucus is known as which condition?

• A. Mucocele
• B. Diverticulitis
• C. Adenoma
• D. Aneurysm

Answer: (A)

Mucocele describes distention of the appendix (and sometimes a portion of the colon) with mucus due to luminal obstruction, causing a dilated, mucus-filled structure. It can arise from simple obstruction or from a mucin-producing mucinous neoplasm. On ultrasound you’d see a well-defined, cystic-appearing structure in the right lower quadrant that runs with the cecum and may contain anechoic content with possible internal echoes if the mucus is thick; the wall is usually thin and Doppler shows little or no internal flow. A key clinical point is that rupture can spread mucin into the peritoneum, leading to pseudomyxoma peritonei. The other conditions described—diverticulitis, adenoma, and aneurysm—do not present as mucus-filled dilation of the appendix or colon.