Malignant transformation of presumed pleomorphic adenoma of lacrimal gland after 60 years.

A woman was diagnosed as having a benign lacrimal gland mass at age 23 years and no treatment was advised. About 60 years later, the previously stationary proptosis began to increase, and biopsy specimens demonstrated a malignant mixed tumor (pleomorphic adenocarcinoma) of the lacrimal gland. The patient was subsequently treated with orbital exenteration. From the clinical history and histopathologic findings, it appears that the patient harbored a long-standing pleomorphic adenoma (benign mixed tumor) that gave rise to a pleomorphic adenocarcinoma after remaining stationary for 60 years.