Ghon’s focus is found in
**Core Concept**
Ghon's focus is a small area of necrotic lung tissue that represents the primary site of infection in primary pulmonary tuberculosis. It is a characteristic lesion in the early stages of the disease.
**Why the Correct Answer is Right**
Ghon's focus is typically found in the upper lobe of the lung, often in the apical or posterior segment. The lesion is usually surrounded by a zone of inflammation and is associated with the formation of a Ghon's complex, which includes the primary site of infection, the associated lymph nodes, and the pleura. The Ghon's focus is a result of the body's immune response to the Mycobacterium tuberculosis infection.
**Why Each Wrong Option is Incorrect**
**Option A:** This is incorrect because Ghon's focus is not found in the lower lobe of the lung, which is more commonly associated with secondary pulmonary tuberculosis.
**Option B:** This is incorrect because Ghon's focus is not a characteristic lesion of primary pulmonary tuberculosis in other parts of the body, such as the skin or lymph nodes.
**Option C:** This is incorrect because Ghon's focus is not a result of a different type of infection, such as pneumonia or bronchitis.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the Ghon's complex, which includes the Ghon's focus, associated lymph nodes, and pleura, is a characteristic finding in primary pulmonary tuberculosis. This complex is often seen on chest radiographs and is a key diagnostic feature of the disease.
**Correct Answer:** C. Lung.