Clinical aspects of alveolar rhabdomyosarcoma with translocation t(1;13)(p36;q14) and hypotetraploidy

Pax3-fkhr and pax7-fkhr fusion genes impact outcome of alveolar rhabdomyosarcoma in children

Rhabdomyosarcoma is a highly malignant embryonic tumor of childhood. Two specific translocations t(2;13)(q35;q14) and t(1;13)(p36;q14) have been identified in about 75-80% of ARMS cells. The aim of this multicenter study was to analyze the relationships between the identified fusion transcripts and survival including some selected clinical parameters. The extent of disease was graded according to clinical staging system with following distribution: 3 children with stage I, 4 with stage II, 23 with stage III, and 18 with stage IV spread disease having distant metastases. PAX3-FKHR fusion genes were detected in 28 and PAX7-FKHR fusion genes in 7 tumor biopsy specimens. Children with PAX3-FKHR fusion gene had often distant metastases at presentation (p = 0.03). PAX3-FKHR positive patients with locoregional disease had significantly poorer outcome compared with the ones with PAX7-FKHR positive tumors (p = 0.04). Although analyzed groups were small, significant differences in survival and clinical characteristics between PAX3-FKHR and PAX7-FKHR positive tumors were stated indicating their role in carcinogenesis. In addition, fusion gene analysis is a helpful tool in differential diagnosis of poorly differentiated soft tissue tumors.

Rhabdomyosarcoma: cytogenetics of five cases using fine-needle aspiration samples and review of the literature

Cytogenetic analyses of fine-needle aspiration samples were performed on five cases of which three were alveolar rhabdomyosarcomas (RMS), one was embryonal RMS and one was RMS of mixed alveolar and embryonal histology. Three cases of alveolar RMS and one case of embryonal RMS showed t(2;13). A del(1)(p11) in a mixed alveolar and embryonal RMS was observed without the presence of t(2;13). add(17)(q25) was present in one of the alveolar RMS along with a t(2;13). Modal number of chromosome in the five cases ranged from hyperdiploid to hypertetraploid. Clinical, cytological, histopathological and cytogenetic findings are correlated. The role of additional abnormalities is discussed with a review of appropriate literature.

Flow Cytometry: Principles and Clinical Applications in Hematology

The use of flow cytometry in the clinical laboratory has grown substantially in the past decade. This is attributable in part to the development of smaller, user-friendly, less-expensive instruments and a continuous increase in the number of clinical applications. Flow cytometry measures multiple characteristics of individual particles flowing in single file in a stream of fluid. Light scattering at different angles can distinguish differences in size and internal complexity, whereas light emitted from fluorescently labeled antibodies can identify a wide array of cell surface and cytoplasmic antigens. This approach makes flow cytometry a powerful tool for detailed analysis of complex populations in a short period of time. This report reviews the general principles in flow cytometry and selected applications of flow cytometry in the clinical hematology laboratory.