**Question:** Herberdens nodes are seen in:

A. Carcinoma of the oral mucosa
B. Carcinoma of the skin
C. Carcinoma of the lung
D. Carcinoma of the breast

**Core Concept:** Herberdens nodes or Paget's disease of the nipple is a rare condition characterized by intraepithelial carcinoma that spreads to the adjacent nipple-areola complex, causing skin changes and sometimes pain.

**Why the Correct Answer is Right:** Herberdens nodes are associated with intraepithelial carcinoma of the breast (ductal or lobular) spreading to the nipple-areola complex. The nipple-areola complex is a part of the skin, so the correct answer is D.

**Why Each Wrong Option is Incorrect:**

A. Carcinoma of the oral mucosa is unrelated to Herberdens nodes as it involves the oral cavity, not the nipple-areola complex.
B. Carcinoma of the skin is incorrect because Herberdens nodes are associated with breast cancer, not skin cancer.
C. Carcinoma of the lung is irrelevant to Herberdens nodes as lung cancer does not affect the nipple-areola complex.

**Clinical Pearl:** In clinical practice, recognizing Herberdens nodes is crucial for prompt diagnosis and management of underlying breast cancer. The presence of skin changes in the nipple-areola complex should prompt a thorough clinical examination for the presence of breast lesions, such as palpable masses, nipple retraction, or discharge.

**Correct Answer:** D. Carcinoma of the breast