This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
Cholesteatoma commonly perforates: 
Select and explain. 
A. Lat. Semicircular canal, B. Sup. semicircular canal, C. Promontory, D. Oval window
A: Lat. Semicircular canal
Answer: A: Lat. Semicircular canal 
Explanation: Ans. is a i.e. Lateral semicircular canal Cholesteatoma has the propey to destroy the bone by viue of the various enzymes released by it. Structures immediately at the risk of erosion are: - Long process of incus.deg - Fallopian canal containing facial nerve.deg - Horizontal/lateral semicircular canal.deg