SOLID ALVEOLAR RHABDOMYOSARCOMAS WITH THE T(213) - REPORT OF 2 CASES WITH DIAGNOSTIC IMPLICATIONS

Two patients having rhabdomyosarcomas with the recently described ''so lid variant'' pattern of alveolar rhabdomyosarcoma are reported. Both tumors had aggressive cytologic features with monotonous sheets of rou nd nuclei, but without fibrous septa, and both had been initially clas sified as embryonal rhabdomyosarcomas. Cytogenetic analyses of tumor e xplants from both cases revealed the t(2;13) chromosomal aberration ty pical of alveolar rhabdomyosarcoma. Both patients died of metastases, despite aggressive surgical and adjuvant therapy. This report represen ts the first karyotypic analyses of solid alveolar rhabdomyosarcomas a nd supports the inclusion of these tumors in the alveolar category des pite the lack of fibrous septa.