Cystic carcinoma ex pleomorphic adenoma of the lacrimal gland.

In a 48-year-old male patient, a well-circumscribed, round tumor in the lacrimal fossa was detected by CT. During total excision of the tumor, a wall of the tumor ruptured, resulting in leakage of the fluid contents. The wall of the tumor formed a cyst that contained residual yellowish fluid. Histologically, the cyst wall included an adenocarcinomatous component and a focus of pleomorphic adenoma. The tumor was diagnosed as a carcinoma ex pleomorphic adenoma of the lacrimal gland. The carcinoma cells showed positive immunoreactivity for androgen receptor and BRST-2, indicating that the tumor was equivalent to a salivary duct carcinoma. Postoperatively, the patient underwent involved field irradiation. This case demonstrates that a carcinoma ex pleomorphic adenoma of the lacrimal gland may develop in a cyst.