Solitary skin metastasis of papillary thyroid carcinoma

A solitary skin metastasis is a rare manifestation of papillary thyroid carcinoma (PTC). A 55-year-old woman presented with a movable subcutaneous nodule in her anterior neck for several months. Three years ago, she underwent total thyroidectomy and remnant ablation for classical PTC (pT3N0M0) and was under thyroxine suppression therapy without any evidence of recurrent disease. The subcutaneous nodule was 0.4 cm in size, firm, and movable without any change in the overlying skin. Recurrent PTC was confirmed after excision biopsy. Eight months after, she got a new nodule along the previous excision site. After punch biopsy, metastatic PTC was confirmed in the deep dermis and was re-excised with a clear resection margin. This is the first report of a case of solitary skin metastasis of PTC in Korea. Although solitary skin metastasis of PTC is rare, it should be considered in patients with a skin nodule.