Orbital granular cell tumor developing in the inferior oblique muscle.
OBJECTIVE
To describe the magnetic resonance imaging and histopathologic features of an orbital granular cell tumor.


METHODS
A 43-year-old man was initially examined with slowly progressive vertical diplopia. A firm mass was palpable through the left lower eyelid. Magnetic resonance imaging and histopathologic examinations were performed.


RESULTS
Magnetic resonance imaging disclosed a spindle-shaped mass involving the inferior oblique muscle. Histopathologic examination disclosed that the tumor cells, diagnosed as a granular cell tumor, had infiltrated the muscle fibers.


CONCLUSIONS
In the present case, these findings indicate that the granular cell tumor may develop in the inferior oblique muscle.
Hashimoto
M
M
Department of Ophthalmology, Sapporo Medical University, School of Medicine, Japan.
Ohtsuka
K
K
Suzuki
T
T
Nakagawa
T
T
D000328:Adult; D003287:Contrast Media; D004172:Diplopia / Q000209:etiology; D019786:Gadolinium DTPA; D016586:Granular Cell Tumor / Q000150:complications / Q000473:pathology* / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D019042:Muscle Neoplasms / Q000150:complications / Q000473:pathology* / Q000601:surgery; D009801:Oculomotor Muscles / Q000473:pathology* / Q000601:surgery; D009918:Orbital Neoplasms / Q000150:complications / Q000473:pathology* / Q000601:surgery
D003287:Contrast Media; D019786:Gadolinium DTPA