**Question:** Egg-shell calcification in hilar lymph nodes is seen in:

**Core Concept:** Egg-shell calcification refers to a unique pattern of calcification in lymph nodes, where the outer rim is dense and the inner core is less dense. This can be observed in certain clinical scenarios.

**Why the Correct Answer is Right:** Egg-shell calcification is primarily seen in tuberculosis (TB) infection, particularly in the lungs. In this context, the dense outer rim represents the initial calcification of caseous necrosis, while the less dense inner core represents the ongoing caseous necrosis and subsequent calcification.

**Why Each Wrong Option is Incorrect:**
A. Calcification in chronic lymphocytic lymphoma (CLL) or lymphoma typically involves the entire lymph node, with a uniform density.
B. Calcification in sarcoidosis is also diffuse and uniform, without the distinct egg-shell pattern.
C. Calcification in amyloidosis is also uniform and does not have the egg-shell appearance.
D. Calcification in Kaposi's sarcoma is patchy and not the characteristic egg-shell pattern seen in TB.

**Clinical Pearl:** Egg-shell calcification in hilar lymph nodes should prompt the suspicion of tuberculosis, as it is a specific radiographic finding associated with pulmonary tuberculosis. This can help guide the diagnostic process and initiate appropriate investigations and treatment.

**Correct Answer:** D. Calcification in Kaposi's sarcoma is patchy and not the characteristic egg-shell pattern seen in TB.