Following an apparently complete canal wall down mastoidectomy for cholesteatoma, a patient returns with recurrent disease. Imaging shows residual keratin deep in a recess medial to the facial nerve that was not fully exenterated. Which recess is this?
- A Prussak's space
- B Facial recess
- C Sinus tympani ✓
- D Anterior epitympanic recess
Correct answer: C. Sinus tympani
Explanation
The sinus tympani lies medial to the pyramidal eminence and facial nerve, between the ponticulus superiorly and subiculum inferiorly. It is hidden from direct microscopic view, making it the commonest site of residual cholesteatoma after surgery. The facial recess lies lateral to the facial nerve and is deliberately opened via a posterior tympanotomy, so it is accessible and not the classic blind pocket.
Reference: Scott-Brown's Essential Otorhinolaryngology, 2nd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.