**Core Concept**
The man's symptoms suggest a condition affecting the ear, specifically the external auditory canal, leading to a discharge. This is likely a result of an infection or a pathological process affecting the skin and mucous membranes in the ear canal.

**Why the Correct Answer is Right**
The characteristic feature of a lesion causing scanty, foul-smelling, painless discharge from the ear is a cholesteatoma. A cholesteatoma is an abnormal skin growth in the middle ear behind the eardrum. It is a type of skin cyst that can cause a discharge due to the accumulation of skin debris and keratin. The discharge is often foul-smelling due to the presence of bacteria and other microorganisms. Cholesteatomas are often asymptomatic in the early stages but can cause symptoms such as discharge, hearing loss, and ear fullness as they grow.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because a perforated eardrum (tympanic membrane perforation) typically presents with a history of trauma, otitis media, or a previous ear infection. The discharge is often purulent and accompanied by pain.

**Option B:** This option is incorrect because an external ear hematoma (also known as a perichondral hematoma) typically presents with a history of trauma, pain, and a visible mass behind the ear. The discharge is not a characteristic feature of this condition.

**Option C:** This option is incorrect because otosclerosis is a condition affecting the middle ear bones (ossicles) and typically presents with a progressive hearing loss, tinnitus, and a feeling of fullness in the ear. The discharge is not a characteristic feature of this condition.

**Clinical Pearl / High-Yield Fact**
A cholesteatoma is a type of skin cyst that can cause a discharge from the ear, but it is often asymptomatic in the early stages. A high index of suspicion is required to diagnose this condition, especially in patients with a history of recurrent ear infections or hearing loss.

**Correct Answer: C. Cholesteatoma**