CK7 negative anaplastic thyroid carcinoma presenting as cutaneous metastases to the scalp

Anaplastic thyroid carcinoma (ATC) is an extremely rare but aggressive form of thyroid cancer. Although local tissue invasion is characteristic of this disease, systemic metastases are a common clinical finding. Our case discusses an unusual presentation of cutaneous metastases to the scalp in a patient with a remote history of ATC. It also highlights the utility of immunohistochemical staining in determining the origin of a tumor when the source of primary malignancy is not readily identifiable.