Leiomyolipoma of the orbit

Orbital leiomyolipoma is a rare benign tumor characterized by a mixture of mature smooth muscle cells and adipocytes. The authors present a case which, to the best of their knowledge, is the second case of leiomyolipoma of the orbit reported in the ophthalmic literature. A 65-year-old patient presented with a painful and swollen left eye, the symptoms having been present for 1 week. Imaging (CT, MRI follow up) confirmed the presence of a nearly 2-cm lesion medial to the lacrimal gland. A biopsy was planned, and 3 specimens were taken for histologic examination. Histology showed diffusely intermingling smooth muscle cells and mature adipocytes; immunohistochemistry demonstrated positive staining for smooth muscle actin and negativity for HMB45, MART-1, and Cytokeratin AE1/3. Although it is very rare, ophthalmologists should consider leiomyolipoma in the differential diagnosis of orbital tumors. The long-term prognosis for patients affected by this benign tumor is good.