Alveolar soft part sarcoma (ASPS) is a rare, histologically distinctive soft-tissue sarcoma typically occurring in children and young adults. Although it displays a relatively indolent clinical course, the ultimate prognosis is poor and is often characterised by late metastases. ASPS is characterised by an unbalanced translocation: der(17)t(X:17)(p11;q25). This translocation causes the fusion of the TFE3 (transcription factor binding to IGHM enhancer 3) with a novel gene at 17q25, named ASPL. Translocation between chromosomes X and 17 is seen in all the tested cases, implicating transcriptional deregulation in the pathogenesis of this tumor.
