Detection of BRAFV600E mutation on papillary thyroid carcinoma and metastatic malignant melanoma by fine-needle aspiration cytology: how genetic testing may drive toward personalized medicine.

A genetic link between cutaneous melanoma and thyroid cancer (TC) has been identified. A high percentage of both melanomas and papillary carcinomas of the thyroid harbors a recurrent mutation (i.e., BRAF(V600E) ) in the BRAF oncogene. Herein, we report the case of a 65-year-old man with papillary TC and cutaneous malignant melanoma metastatic to masseter muscle, both characterized by BRAF mutation. This is one of the rare reports in which a complete molecular characterization has been performed. As the patients with papillary thyroid carcinoma have a higher risk of malignant melanoma and vice versa, continuous monitoring of such patients, with either of these tumors is necessary. Fine-needle aspiration cytology is useful as shown in the present case.