Pleomorphic Adenoma: (1,2) This benign intrinsic tumor of the lacrimal gland usually presents as a painless, slow growing mass in healthy adults. Also referred to as benign mixed tumor, it is the most common lacrimal epithelial tumor. Patients present with a firm, lobular mass in the lacrimal fossa, often with medial and inferior displacement of the globe. Computed tomography is best for imaging this smooth, globular lesion that may show contouring of the bone but not destruction or infiltration. Since tumor cells have the potential for malignant degeneration, excisional biopsy or complete resection is performed. These residual cells can proliferate and infiltrate orbital structures, requiring extensive surgery for removal. Microscopically, pleomorphic adenomas have a varied cellular appearance. Areas of benign epithelial proliferation and double cell lined lumens filled with mucus are intermixed with myxoid stroma, populated sparsely by spindle shaped cells. Back to Orbit