The patient presented to BPEI for evaluation of a two-week history of worsening diplopia. Examination revealed left unilateral proptosis. MRI orbit imaging revealed an intraorbital well-defined, well-circumscribed lesion arising at the level of the medial rectus. The patient underwent an incisional biopsy which revealed cells with eosinophilic, granular cytoplasm, and bland nuclei. The tumor stained positive for S-100, NSE, SOX10, and CD68. The trichrome stain showed collagenous material. The granules were PAS-positive and diastase resistant. The patient was diagnosed with a granular cell tumor. The clinical team is planning proton beam irradiation therapy and surgical resection of the tumor.
Presentation Date: 08/26/2021
Issue Date: 10/22/2021