Primary cutaneous adenoid cystic carcinoma: an unusual case.

Primary cutaneous adenoid cystic carcinoma (PCACC) is an uncommon adnexal skin tumor. It is usually located on the head or neck of people over 50 years of age, affecting men and women equally. The etiology is unclear; the source used to be considered the eccrine glands, but more recent hypotheses defend this carcinoma as originating in the apocrine glands or modified apocrine glands. The tumor may clinically appear as a normal skin-colored nodule with ill-defined edges and slow growth. Histologically, a proliferation of neoplastic cells appears, which could present in a tubular, cribriform, or solid pattern. Perineural invasion is characteristic for this tumor. For diagnosis of PCACC it is essential to exclude metastasis, especially in the salivary glands. Treatment involves surgical excision. We present a case of primary adenoid cystic carcinoma in a young woman located on the skin of the upper limb, which is an unusual place.