Lacrimal gland malignant mixed tumors (carcinomas arising in benign mixed tumors): a clinico-pathologic study

Six cases of a rare entity, lacrimal gland malignant mixed tumor (MMT), or carcinoma arising in benign mixed tumor (BMT), are presented. Clinically, 2 patients had a long history of orbital protrusion, which recently had progressed more rapidly, In 2 other cases, the carcinomas evolved after recurrences of BMT. Two other patients experienced the recent onset of symptoms, without a known tumor previously having been present. Clinical clues suggesting a malignant neoplasm of a lacrimal gland include 1) recent rapid onset of symptoms (orbital protrusion, eyelid swelling; 2) presence of pain; and 3) radiographic studies showing bone destruction. In each of our cases, histologic examination demonstrated a BMT as well as a carcinoma (undifferentiated or poorly differentiated adenocarcinoma; in 1 case, areas of adenoid cystic carcinoma were identified). Problems in histopathologic diagnosis are explored. (BMT, recurrent BMT, in situ carcinoma in BMT and MMT are differentiated.) The management of lacrimal gland tumors is discussed. For a suspected malignant neoplasm, a biopsy through the eye lid to establish the diagnosis is recommended. Radical orbital exenteration should be performed for malignant mixed tumors, which have a poor prognosis.