Granular Cell Tumor in the Medial Rectus Muscle: A Case Report.

An 80-year-old female complained of diplopia after undergoing cataract surgery. On the first examination, adduction and abduction were slightly restricted. Magnetic resonance imaging revealed a mass in the medial rectus muscle. The results of pathological examination of a specimen harvested from the mass corresponded to granular cell tumor. Although we could not completely excise the mass because of firm adhesion of the mass to the muscle, there was no recurrence without any suspicious metastatic lesion at 2.5 years of follow-up.