[Alveolar sarcomas of soft tissues. Immunohistochemical, ultrastructural study and flow cytometry].

Alveolar soft tissue sarcoma is an unusual tumor, known to have a poor prognosis. Although a muscular origin has been supported by most authors, the histogenesis of such tumors remains unclear. We report a case of alveolar soft tissue sarcoma with histological, ultrastructural, immunohistochemical and flow cytometry study. Pour results support a myogenic origin of these tumors and demonstrate its aneuploid nature. Pulmonary metastasis occurred early in spite of intensive chemotherapy and surgical removal of the tumor.