Primary adenoid cystic carcinoma of the eyelid.

Adenoid cystic carcinoma is a rare epithelial malignancy, which tends to grow slowly. It is an intractable neoplasm due to its ability to invade perineural spaces. A 59-year-old female presented with a gradually increasing mass in the right lower eyelid. An excisional biopsy with wide margins revealed a diagnosis of primary adenoid cystic carcinoma of eyelid skin with perineural invasion. Although a rare neoplasm, primary adenoid cystic carcinoma of eyelid skin should be included in the differential diagnosis of eyelid tumors.