**Question:** Transmural involvement & granuloma are seen in -

A. Tuberculosis
B. Crohn's disease
C. Leprosy
D. Tumors

**Core Concept:**
Transmural involvement refers to the spread of inflammation beyond the mucosal and submucosal layers into the muscularis and serosa layers of the gastrointestinal tract. Granulomas are non-caseating, inflammatory lesions composed of macrophages, lymphocytes, and epithelioid cells. Both of these features are commonly observed in certain diseases.

**Why the Correct Answer is Right:**
A. Tuberculosis: Granulomas are a hallmark of Mycobacterium tuberculosis infection and can be seen in transmural involvement of the affected organs, including the lungs, lymph nodes, and gastrointestinal tract.

B. Crohn's disease: Transmural involvement is a key feature of Crohn's disease, a type of inflammatory bowel disease (IBD) that can affect any part of the gastrointestinal tract. Granulomas are not a common feature in Crohn's disease, although they can be seen in certain cases, particularly in the small intestine.

C. Leprosy: Granulomas are a characteristic finding in leprosy caused by Mycobacterium leprae. Transmural involvement is also a feature of leprosy affecting different organs, including the skin, nerves, and viscera.

D. Tumors: Granulomas are not typically seen in tumors, which are characterized by abnormal cell growth. Granulomas are usually associated with infectious or inflammatory diseases.

**Why Each Wrong Option is Incorrect:**
A. Tumors: Granulomas are not seen in tumors, which are characterized by abnormal cell growth. Granulomas are usually associated with infectious or inflammatory diseases.
B. Crohn's disease: While transmural involvement is a feature of Crohn's disease, granulomas are not a common finding in this condition. They can be seen in some cases, particularly in the small intestine.
C. Leprosy: While granulomas are a characteristic finding in leprosy caused by Mycobacterium leprae, the question asks for the presence of transmural involvement and granulomas in diseases. Leprosy does involve transmural involvement, but granulomas are more commonly associated with other diseases like tuberculosis and sarcoidosis.
D. Tumors: Granulomas are not seen in tumors, which are characterized by abnormal cell growth. Granulomas are usually associated with infectious or inflammatory diseases.

**Clinical Pearl:**
Granulomas are seen in granulomatous diseases, which are characterized by the formation of granulomas due to the presence of foreign bodies like bacteria, parasites, or immune complex deposition. Granulomatous diseases can involve transmural involvement, as seen in tuberculosis, sarcoidosis, and leprosy. Tumors are not associated with granulomas, as they are characterized by abnormal cell growth rather than foreign body granulomas.

In summary, granulomas are typically seen in diseases involving foreign bodies or immune complex deposition, such