Cholesteatoma recurs after a canal wall up procedure despite apparent complete removal. Imaging shows disease in a deep recess of the posteromedial middle ear that is not accessible through the facial recess. Which structure has been involved?

• A Facial recess
• B Sinus tympani ✓
• C Prussak space
• D Anterior epitympanic recess

Explanation

The sinus tympani is a deep, blind pocket on the posteromedial wall lying medial to the facial nerve and pyramidal eminence, limited inferiorly by the subiculum and superiorly related to the ponticulus. Because it sits medial to the facial nerve, it cannot be accessed via the facial recess and is the classic site of residual cholesteatoma. The facial recess lies lateral to the facial nerve, so option A is anatomically impossible here.

Reference: Scott-Brown's Otorhinolaryngology and Head and Neck Surgery, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.