Malignant Mixed Tumor (Carcinoma Ex Pleomorphic Adenoma) of the Lacrimal Gland

Purpose: To review the clinical presentation, treatment, and prognosis of patients with malignant mixed tumor (carcinoma ex pleomorphic adenoma) of the lacrimal gland. Methods: Clinical records and radiographic images were reviewed for patients with malignant mixed tumor of the lacrimal gland treated at the center during 2008-2019. Results: The study included 9 patients (6 men, 3 women) aged 17-66 years (median age, 56 years). Six had primary malignant mixed tumor with no history of orbital lesions, and 3 had previously been diagnosed with pleomorphic adenoma. Tumor, Node, Metastasis classification per the eighth edition of the American Joint Committee on Cancer (AJCC) Cancer Staging Manual were T1aN0M0 in 2 patients, T2aN0M0 in 3 patients, T4bN0M0 in 2 patients, and T4cN0M0 in 2 patients. Two patients underwent orbital exenteration, 6 patients underwent eye-sparing surgery, and 1 patient had an unresectable tumor because of cavernous sinus extension. All patients received radiotherapy (intensity-modulated radiotherapy in 3 and proton therapy in 6). All patients received chemotherapy, 8 concurrently with radiotherapy and 1 after radiotherapy. The median follow-up time was 70 months. At last contact, 6 patients were alive without evidence of disease; 2 had died of disease, 1 of distant metastasis, and the other of cavernous sinus invasion. Conclusions: The findings suggest that de novo malignant mixed tumor of the lacrimal gland is more common than disease that results from transformation after incomplete resection of lacrimal gland pleomorphic adenoma. Most cases can be treated with eye-sparing surgery and radiation unless skull base extension is present.