Orbital intramuscular hemangioma enlarging during pregnancy.

A 31-year-old pregnant woman presented with subacute painful proptosis due to an orbital apex mass arising from the right medial rectus muscle. The patient developed compressive optic neuropathy refractory to systemic prednisone and underwent orbitotomy with posterior orbital decompression through a transcaruncular approach. Pathologic examination showed intramuscular hemangioma, a benign vascular hamartoma of skeletal muscle, which rarely occurs in the orbit. The optic neuropathy and proptosis resolved without consecutive strabismus or enophthalmos.