Primary cutaneous adenoid cystic carcinoma metastasising to the kidney.

Adenoid cystic carcinoma (ACC) is a rare head and neck cancer; even more infrequently, it presents as a primary lesion at other sites. Due to ACC's usual pattern of perineural and perivascular spread, it often manifests in delayed local recurrence and distant metastases. Metastasis to the kidney is very rare with as few as 15 cases reported in the literature. This report presents the case of a woman in her 60s with a history of a cutaneous ACC and a singular lesion in her left kidney that was treated with radical nephrectomy. Histopathology showed complete resection of metastatic ACC. To the best of the authors' knowledge, this is the only documented case of primary cutaneous ACC metastasising to the kidney.