Orbital glomangiopericytoma in a 5-year-old child.

A 5-year-old girl presented with a 6-month history of strabismus and painless left proptosis. Magnetic resonance imaging revealed a homogenously enhancing, anterior, superomedial, left orbital mass. Excisional biopsy established the diagnosis of orbital glomangiopericytoma. Glomangiopericytoma of soft tissue is a perivascular myoid neoplasm with hemangiocytoma-like vascular channels that has overlapping features between glomus tumor and myopericytoma. To the authors' knowledge, glomangiopericytoma of the orbit has not previously been reported.