In August 2016, an 11-year-old boy presented to the authors' institution with a right orbital tumor that was located superotemporally (superolaterally) and adherent to the sclera. The patient's past medical history revealed that he had undergone 2 previous craniotomies elsewhere in June 2008 and July 2010 for a superomedially located orbital lesion that had been histopathologically diagnosed as a neurothekeoma. After the second craniotomy, the patient underwent adjuvant intensity modulated radiotherapy (IMRT) to the right medial orbit. At the authors' institution, total excision of the orbital tumor was performed via an anterior conjunctival orbitotomy. Histopathological examination revealed a rhabdoid meningioma. Review of the histopathology obtained at the time of previous tumor excisions showed that the lesion was misdiagnosed as neurothekeoma and instead represented a meningioma from the beginning. The patient was started on a regimen of oral sunitinib and remained free of recurrence at 1.5 years of follow-up. Ectopic meningioma of the orbit is a rare entity. Rhabdoid meningioma is a rarely seen subtype of meningioma, accounting for 1%-3% of all intracranial meningiomas. To the best of the authors' knowledge, this is the first case of an ectopic orbital rhabdoid meningioma reported in the literature. They suspect that tumor seeding during the previous surgeries might have played a role in the occurrence of the tumor in an orbital location not targeted by IMRT.
Keywords: EMA; IMRT; RM; ectopic meningioma; epithelial membrane antigen; immunohistochemistry; intensity modulated radiotherapy; irradiation; magnetic resonance imaging; oncology; orbit; orbitotomy; pathology; pediatric; rhabdoid meningioma; sunitinib; surgery.