Alveolar soft part sarcoma as unusual cause of a slow growing subcutaneousmass

Background: A slow growing indolent subcutaneous mass can be caused by a va riety of benign and malignant soft tissue proliferations, however, it is of ten the first sign of soft tissue sarcomas. Radiological findings are unspe cific and biopsy with histopathological analysis is needed. Method: Three female patients (age 9, 191/12 and 232/12 yeats) are presente d with a slow growing subcutaneous mass, which was shown to be a malignant non-embryonal soft tissue sarcoma (alveolar soft part sarcoma). Results: Alveolar soft part sarcoma (ASPS) is a very rare malignancy. At di agnosis, 2 patients already had metastatic disease. One girl died before th erapy, the other one suffers from slowly progressive pulmonary metastases 4 1/2 years after diagnosis, despite multi-modal treatment approaches. The th ird patient received polychemotherapy and total irradiation after complete tumor resection and is free of disease 8 months after diagnosis. Conclusion: ASPS is a rare slow growing malignancy with an extraordinary te ndency to metastasitc. The prognosis depends on wether the tumor is operabl e and whether there are metastases.