Gastrointestinal Stromal Tumor Metastasis to the Orbit

A 66-year-old woman was referred to the authors' service with a 1-week history of blurry vision in her left eye and retro-orbital ache. She had previously undergone a radical distal gastrectomy and omentectomy for gastrointestinal stromal tumor, epithelioid type, 7 years prior. Exophthalmometry confirmed 2mm of left-sided proptosis. Computed tomography imaging revealed a solid-appearing mass straddling both the intra- and extraconal spaces and involving the superior rectus muscle. An excisional biopsy was performed. Histopathological examination revealed a relatively uniform epithelioid appearance with a high mitotic rate, and immunohistochemical analysis revealed positivity for both KIT (CD117) and CD34. To the best of the authors' knowledge, this is only the second histopathologically confirmed case of gastrointestinal stromal tumor metastasis to the orbit reported in the literature.