Cutaneous metastasis of breast adenoid cystic carcinoma to the scalp.

Adenoid cystic carcinoma (ACC) is a tumor that can be of primary cutaneous origin or secondary to metastatic disease, most commonly salivary origin. Aside from primary cutaneous and salivary types, ACC of the breast is a rare, more indolent variant. Cutaneous metastases secondary to breast ACC is exceedingly uncommon and not previously reported to our knowledge. We present the case of a 67-year-old woman who developed cutaneous metastasis from primary breast ACC.