[Primary cutaneous extraskeletal Ewing's sarcoma].

BACKGROUND: Cutaneous extraskeletal Ewing's sarcoma is rare, being seen principally in children. We report a case of cutaneous sarcoma in the sole of the foot in a child. CASE REPORT: A 9-year-old child with no medical history of note was presenting a skin tumor for 3 months on the heel of the right foot. This tumor was burgeoning and painful and measured 3.5 cm in diameter; it was ulcerative at the surface and covered with a crust. Histological and immunohistochemical examinations confirmed the diagnosis of Ewing's sarcoma. Staging examinations proved negative and the patient underwent polychemotherapy, resulting in complete regression of the tumor. COMMENTS: Until 1998, 37 cases of cutaneous and subcutaneous Ewing's sarcoma were reported, being seen in 21 girls and 16 boys. Mean age at diagnosis was 15 years and mean tumor size was 3 cm (range: 1 to 12 cm). The tumors were observed throughout the body, being seen in the sole of the foot in 2 cases. Confirmation of the diagnosis was made by histological examination (malignant proliferation of small round cells in the dermis), immunohistochemical examination (CD99+) and cytogenetic analysis (translocation between chromosomes 22 and 11). The prognosis for cutaneous Ewing's sarcoma appears more favorable than that of Ewing's sarcoma in bone. Of the 37 patients treated, 7 had metastases and 2 presented relapse. Treatment for cutaneous Ewing's sarcoma, though not codified, consists of polychemotherapy associated with surgery and/or radiotherapy.