Isolated intraosseous extra-gnathic orbital myxoma: a clinicopathologic case report

A 19-year-old female student presented with painless, progressive proptosis in the right eye for the past six months causing significant cosmetic blemish and double vision. Clinical evaluation revealed normal visual acuity, normal pupillary reflex, severe proptosis, and dystopia. Orbital imaging revealed a heterogeneous mass in superior orbit displacing the globe inferiorly and causing extensive bony erosion of frontal bone superiorly and invading the frontal sinus. Excision biopsy was performed with en-bloc removal of the tumor. Surgical delivery of a slimy mass with infiltrated bony tissue led to a presumptive diagnosis of myxoid liposarcoma. Careful histopathologic analysis coupled with immunohistochemical studies were performed which established the rare diagnosis of low-grade myxoid spindle cell neoplasm with features suggestive of intraosseous myxoma. On follow-up at 15 months, our patient revealed no signs of recurrence. Isolated intraosseous orbital myxoma is a rare entity; only two such cases have been reported in the literature.