A rare case of mucoepidermoid carcinoma ex pleomorphic adenoma of the lacrimal gland

Carcinoma ex pleomorphic adenoma (CEPA) of the lacrimal gland is a rare malignant tumor that arises from a pre-existing pleomorphic adenoma. Lacrimal gland CEPA with mucoepidermoid histological subtype is exceedingly rare. Diagnosis can be aided by radiographic findings, though the gold standard is histopathological analysis following excisional biopsy. Management options include complete surgical excision with or without adjuvant radiation therapy based on tumor grade and invasiveness. We present a 76-year-old woman with 6 months of diplopia and unilateral proptosis. Her initial exam was remarkable for hypoglobus, proptosis, and limited elevation of the right eye. Computed tomography (CT) scan demonstrated a superior, well-circumscribed, extraconal orbital mass. An excisional biopsy was performed, and histopathological findings were consistent with mucoepidermoid carcinoma ex pleomorphic adenoma with positive margins in the tumor capsule. The patient received radiation therapy and remains markedly improved with no disease recurrence at 5 months post-operatively.