Synchronous Papillary and Follicular Carcinoma with Scalp and Nodal Metastasis: A case report with review of literature.

Collision tumor comprise of existence of two histologically distinct and separate neoplasms in any organ. Thyroid gland is an uncommon site for these tumors, with frequently involved organs being liver, adrenal and stomach. Even among the synchronous tumors of thyroid, papillary and medullary carcinoma are most commonly reported. The present case reports a rare presentation of a collision tumor comprising of papillary and follicular carcinoma with scalp metastasis from the follicular carcinoma and lymph nodal metastasis from the papillary component. It is essential for the clinician to be aware of such an entity so as to guide further treatment and management.