Gastric Cancer: The left supraclavicular lymph node is often referred to as the "Virchow's node." Enlargement of this node can be a sign of metastasis from abdominal malignancies, with gastric cancer being a classic cause due to its propensity to spread through the lymphatic system to this specific location.

Lung Cancer: Given the proximity of the supraclavicular lymph nodes to the lungs, lung cancer is a common cause of lymphadenopathy in this area, especially for cancers originating in the upper lobes.
Breast Cancer: In women, breast cancer can metastasize to the supraclavicular lymph nodes, particularly if the cancer is located in the upper outer quadrant of the breast.
Lymphoma: Both Hodgkin's and non-Hodgkin's lymphoma can cause supraclavicular lymphadenopathy, as these cancers often involve multiple lymph node groups.
Infections (e.g., Tuberculosis): Chronic infections such as tuberculosis can cause lymphadenopathy in any location, including the supraclavicular area.

Abdominal Malignancies (e.g., Pancreatic, Ovarian): While less common than gastric cancer, other abdominal malignancies can also metastasize to the left supraclavicular lymph node, making them crucial not to miss due to their significant impact on prognosis and treatment.
Thyroid Cancer: Though less common, thyroid cancer can metastasize to the supraclavicular lymph nodes, and missing this diagnosis could lead to delayed treatment of a potentially curable cancer.

Sarcomas: Rarely, sarcomas (cancers of bone, muscle, or connective tissue) can metastasize to the supraclavicular lymph nodes.
Testicular Cancer: Some testicular cancers, particularly those with retroperitoneal lymph node involvement, can rarely metastasize to the supraclavicular lymph nodes.
Melanoma: In patients with a history of melanoma, metastasis to the supraclavicular lymph nodes, although rare, is a possibility and indicates advanced disease.