[Ewing sarcoma in a 12-year-old Gabonese boy].

Ewing sarcoma is a primary malignant bone tumor rarely observed in black populations. We report a case of Ewing sarcoma in a 12-year-old boy, manifested by pain in the lower limbs and pelvis, limping while walking, with functional disability and visual disorders developing over a 2-year period, from 2005 through 2007. The child was transferred for care to South Africa where a biopsy bone was taken and analyzed. The histological slices showed clusters of small round cells, sometimes with indistinct or eosinophilic cytoplasm, oval vesicular nuclei, and fine chromatin. These images were compatible with neoplastic proliferation of small round cells of the Ewing tumor type. We use this case to review the literature and discuss the circumstances of onset and methods of diagnosis.