Alveolar soft-part sarcoma. A report of ten cases.

The clinical and pathologic features of ten cases of alveolar soft-part sarcoma (ASPS) were observed in subjects aged ten to 49 years. Eight were male and two were female. The lesion involved the thigh in six cases and the adjacent bone in three. All lesions were retrospectively classified as high risk (Stage II or III of Enneking's staging system), and distant metastasis to lung or bone was noted at initial presentation in four patients. Three patients died with distant metastases at a mean time of three years seven months after diagnosis. The mean interval from initial presentation to detection of distant metastasis was nine months; and the mean interval from detection of metastasis to death was three years two months. Ultrastructural studies demonstrated typical organoid arrangement of the neoplastic cells surrounded by a basement membrane with close attachment of individual cells to the basal lamina. No local recurrence, even in cases with inadequate tumor control, and the tendency for distant metastasis demonstrated in the current series, reemphasized that management of metastasis is most important in the treatment of ASPS.