Metastatic Papillary Thyroid Carcinoma, Follicular Variant
Follicular thyroid carcinoma (FTC) tends to spread via blood-borne route rather than via lymphatics. Nodal metastases in FTC are virtually unknown and invariably turn out to be follicular variant of papillary thyroid carcinoma (as in this case). Hurthle cell carcinoma of the thyroid also has a tendency to spread via hematogenous route to liver, lung, bones, and other distant sites; however, unlike follicular carcinoma, they can also invade lymphatics and spread to regional lymph nodes. Sometimes, intravascular tumor thrombi can get large and present as multiple neck nodules, mimicking nodal metastases.