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: ENT
A man presented with persistent ear pain and discharge, retro-orbital pain and modified radical mastoidectomy was done to him. Patient comes back with persistent discharge, what is your diagnosis? 
Select and explain. 
A. Diffuse serous labyrinthitis, B. Purulent labyrinthitis, C. Petrositis, D. Latent mastoiditis
C: Petrositis
Answer: C: Petrositis 
Explanation: In a patient with CSOM, persistent ear discharge with or without deep seated pain in spite of an adequate coical or modified mastoidectomy points towards petrositis. Spread of infection from middle ear and mastoid to the petrous pa of temporal bone is petrositis it can also involve adjacent 5th cranial nerve and 6" cranial nerve when it produces classical triad of symptoms - 6th nerve palsy, retro orbital pain (5th nerve) and persistent discharge from the ear, known as Gradenigo's syndrome Treatment Adequate drainage is the mainstay of treatment along with specific antibiotic therapy. Modified radical or radical mastoidectomy is often required if not done already. The fistulous tract should be identified, curetted and enlarged to provide free drainage.