Orbital extra-medullary granulocytic sarcoma: clinicopathologic correlation with immunohistochemical features.

Orbital granulocytic sarcoma (chloroma), a rare tumor of immature myeloid cells, has nonspecific clinical and radiological features that make it a diagnostic challenge. Light microscopy and confirmation by immunostaining aid in the diagnosis. Knowledge of this entity is important because early diagnosis and prompt treatment are associated with better prognosis. We report a series of 31 biopsy-proven orbital granulocytic sarcomas with their immunohistochemical features and review the literature.