Metastasis to neck lymph nodes is from?

Ans. (B) Lung cancerRef: Schwartz 10th ed. / 583; Harrison 18th ed/ Ch 99Metastasis to Cervical lymph NodesSquamous cell carcinoma (SCC) is the most common histotype, followed by adenocarcinoma, undifferentiated carcinoma and other malignancies (for example, lymphoma and melanoma)Common site for metastasis to neck nodes - Head and Neck (M.C.), Lungs (2nd M.C.), esophagus, stomatch, ovary, pancreas. Approximately ten percent of patients with abnormal cervical nodes present without obvious primary. Most common sites for unknown primary:* Nasal Pharynx.* Pyriform Sinus.* Tongue Base* Tonsillar Crypts.* Thyroid* Lung.DRAINAGE Sites for Cervical Lymph NodesThe left supraclavicular node is called Virchow's node since it is on the left side of the neck where the lymphatic drainage of most of the body (from the thoracic duct) enters the venous circulation via the left subclavian vein. The metastasis blocks the thoracic duct leading to regurgitation into the surrounding nodes i.e. virchow's node.RememberProbable Source of Nodal Metastasis* Level 1: Oral cavity, submandibular gland.* Level 2: Nasal pharynx, oral pharynx, parotid, superglottic larynx.* Level 3: Oral pharynx, hypopharynx, superglottic larynx.* Level 4: Subglottic larynx, hypopharynx, esophagus, thyroid.* Level 5: Nasal pharynx, oral pharynx.* Level 6 & 7: Thyroid, larynx, lung.* Note: Bilateral nodes are common with cancers of soft pallet, tongue, epiglottis, and nasal pharynx.