## **Core Concept**
Troisier's sign refers to the enlargement of the left supraclavicular lymph node, which is often associated with abdominal malignancies, particularly gastric carcinoma. This sign is a clinical indicator of metastatic disease.

## **Why the Correct Answer is Right**
The correct answer involves the left supraclavicular lymph node. This specific lymph node is significant because it drains lymph from the thoracic duct, which in turn receives lymph from the entire lower body, including the abdomen. Therefore, enlargement of this lymph node can indicate metastasis from abdominal organs.

## **Why Each Wrong Option is Incorrect**
- **Option A:** The right supraclavicular lymph node is not typically associated with Troisier's sign. While it can be involved in various pathologies, Troisier's sign specifically refers to the left side.
- **Option B:** The axillary lymph nodes are not related to Troisier's sign. They are more commonly associated with breast cancer and other upper limb pathologies.
- **Option C:** The inguinal lymph nodes are also not related to Troisier's sign. They are typically involved in pathologies of the lower limbs and pelvic organs.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that Troisier's sign is often associated with gastric carcinoma. The presence of a painless, enlarged left supraclavicular lymph node in a patient with abdominal symptoms should prompt investigation for gastric cancer, among other abdominal malignancies.

## **Correct Answer:** . Left supraclavicular lymph node.