Hemangiopericytoma-solitary fibrous tumor of the eyelid.

The authors report a rare case of hemangiopericytoma-solitary fibrous tumor of the eyelid. A 35-year-old male presented with approximately 1-year history of a painless and slow growing mass on his right lower eyelid, which rapidly grew in size over the last few months. The size of the lesion and the location resulted in secondary mechanical ectropion at presentation. The tumor was excised and was found to be a "hemangiopericytoma-solitary fibrous tumor" based on both histopathological and immunohistochemical examinations. Immunohistochemically, the tumor was positive for CD34 and Vimentin but negative for S100 protein and smooth muscle actin. Although initial tumor removal was complete, the patient required a subsequent operation for his residual ectropion. Despite the lesion being large at presentation, surgical intervention resulted in good functional and cosmetic outcome.