Thyroid carcinoma metastatic to the skin: A cutaneous manifestation of a widely disseminated malignancy

Background: Cutaneous metastases develop in 2% to 9% of patients with an internal malignancy. Thyroid carcinoma metastatic to the skin is a rare clinical entity. Objective: Our purpose was to study the clinical and pathologic features and outcome in patients with cutaneous metastasis from thyroid carcinoma. Methods: The study included a retrospective analysis of six patients with skin metastases from thyroid carcinoma and a review of the English-language literature since 1964. Results: Including our six patients, 43 patients with skin metastases from thyroid carcinoma have been reported. Papillary carcinoma was the most common (41%), followed by follicular (28%), anaplastic (15%), and medullary carcinomas (15%). The scalp was the most common site of metastasis. For our patients, the average length of survival after diagnosis of cutaneous metastasis was 19 months. Conclusion: Cutaneous metastasis from thyroid carcinoma is rare and occurs in the setting of disseminated neoplastic disease.