Primary adenoid cystic carcinoma of skin.

Two primary adenoid cystic carcinomas of skin were studied histologically and histochemically. Histologically, they closely resemble adenoid cystic carcinoma found in other tissues but in the skin must be distinguished from aggressive basal cell carcinomas. The natural history of these tumors and of those collected from the literature suggest a long indolent and progressive course. Local excision with meticulous histologic control of the surgical margins appears to be an appropriate therapeutic strategy. Thus far lymph node metastases have not been observed.