Malignant granular cell tumor metastatic to the orbit.
OBJECTIVE
Malignant granular cell tumor is a rare type of soft tissue sarcoma. To our knowledge, ocular (eyelid) involvement has been described in only two cases. Herein, we report the clinicopathologic features of an unusual case of malignant granular cell tumor metastatic to the orbit.


METHODS
Observational case report.


METHODS
Retrospective review of the medical record and the histopathologic and electron microscopic findings and review of the literature.


RESULTS
A 72-year-old man with biopsy-proven granular cell tumor in the cervical region was initially seen with proptosis and motility disturbance. A magnetic resonance imaging scan showed a large intraconal mass, and biopsy of the orbital mass revealed granular cell tumor. Histopathologic examination of the primary neck tumor and the orbital mass revealed increased nuclear atypia and pleomorphism in the consecutive lesions. The morphologic impression of granular cell tumor was also supported by the immunohistochemical demonstration of S-100 protein expression and ultrastructural findings typical of granular cell tumor. Six months after the orbital involvement, systemic workup revealed multiple apparent bony and lung metastases.


CONCLUSIONS
We report the first malignant granular cell tumor metastatic to the orbit and suggest the inclusion of this tumor in the differential diagnosis of metastatic orbital lesions.
Callejo
S A
SA
Bascom Palmer Eye Institute, University of Miami School of Medicine, Florida 33101, USA.
Kronish
J W
JW
Decker
S J
SJ
Cohen
G R
GR
Rosa
R H
RH
D000368:Aged; D004164:Diphosphonates; D017809:Fatal Outcome; D016586:Granular Cell Tumor / Q000175:diagnosis / Q000532:radiotherapy / Q000556:secondary*; D006258:Head and Neck Neoplasms / Q000473:pathology*; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D008279:Magnetic Resonance Imaging; D008297:Male; D009918:Orbital Neoplasms / Q000175:diagnosis / Q000532:radiotherapy / Q000556:secondary*; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D013125:Spinal Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D017556:Technetium Compounds
D004164:Diphosphonates; D017556:Technetium Compounds; C029045:technetium Tc 99m diphosphonate