Cutaneous metastasis as the presenting sign of papillary thyroid carcinoma

Cutaneous metastasis of visceral tumors accounts for 2% of skin tumors. We report the case of a 71-year-old male with a smoking history who presented to dermatology department with a violaceous nodule of the right sideburn skin. The lesion was interpreted as an adenocarcinoma that was completely excised and was suspicious for a metastasis. There was a recommendation for additional work-up. At a different institution, a positron emission tomography scan showed a left hilar mass and uptake in the right thyroid. He was then referred to our hospital for tissue diagnosis. Mediastinoscopy with biopsy of the left hilar mass showed metastatic follicular thyroid carcinoma. Subsequently, a thyroid fine needle aspirate showed suspicion for malignancy with similar morphology. Thyroidectomy and central neck dissection showed right thyroid papillary carcinoma extending to one margin and involving the lymph nodes. The left hilar metastasis mass resection showed similar lymph node findings. A re-review of the sideburn excision revealed similar histopathology to the thyroid and mediastinal resection. This case illustrates the opportunity of considering metastatic thyroid carcinoma to skin even in cases which lack the classic cytologic and architectural features of papillary thyroid carcinoma follicular variant.