t(5;12)(q31;q24) in childhood acute lymphoblastic leukemia

Novel translocation (9;12)(q22;q24) in secondary chondrosarcoma arising from hereditary multiple exostosis

We report a new translocation in a patient with a history of hereditary multiple exostosis (HME) who developed a recurrent grade I chondrosarcoma involving the sacrum and retroperitoneum. Karyotypic analysis of the tumor revealed a sole chromosome abnormality t(9;12)(q22;q24.3). To our knowledge, this translocation has not been previously identified in either chondrosarcoma, HME, or related tumor types. Our novel translocation may be related to the sarcomatous degeneration of the pre-existing exostosis.

Constitutional balanced translocations in alveolar rhabdomyosarcoma

Chromosomal analysis of tumor tissue from two children with alveolar rhabdomyosarcoma revealed t(1;5)(q32;q31) and t(1;22)(q21;q11.2) in all metaphases examined, respectively. Peripheral blood lymphocytes carried the same cytogenetic abnormality as that of the tumor cells in both patients. Parental lymphocytes were karyotypically normal in the patient with t(1;22), indicating a de novo constitutional translocation, but t(1;5) was paternally inherited in the other patient. The presence of constitutional translocations in these two children might have contributed to the development of alveolar rhabdomyosarcoma.