60 year old man presented with left sided ear discharge for 7 years with dull ear ache. 0/e intact tympanic membrane on both sides, mass is seen in the posterior canal wall on left side. Diagnosis is?

Keratosis Obturans: Also known as canal wall cholesteatoma. It is seen commonly in younger age groups, due to defective epithelial migration from the tympanic membrane to posterior meatal wall, which results in collection of pearly white epithelial debris in deep meatus. It can cause pressure effects, enlargement of bony canal and sometimes facial palsy. Usually patients with conductive deafness and earache. Treatment is removal of entire keratotic mass. Recurrence is common.