[Research on bone marrow involvement in the diagnosis of solid tumors in children. Methods, results and...

The assessment of bone marrow involvement by tumor cells remains an essential problem at diagnosis in pediatric solid tumors. Besides the conventional cytological and histological methods, some modern cell density separation techniques have been described in order to improve the detection of minimal or scattered bone marrow involvement. Immunological or genetical (molecular biology) tools can be used for the recognition of separated cells. In terms of investigations, MRI and MIBG radionucleide scan, although giving no definite proof, have the ability to macroscopically study the scattering of bone marrow invasion in the particular case of neuroblastoma. In some pediatric tumors, especially neuroblastomas and non Hodgkin lymphomas, an extensive bone marrow investigation is mandatory at diagnosis. Such an investigation is only necessary in case of particular criteria at diagnosis of Hodgkin's disease, Ewing' sarcomas, rhabdomyosarcomas and retinoblastomas. All other pediatric solid tumors do not need to be investigated in terms of bone marrow involvement at diagnosis, with the exceptions of advanced disseminated disease or if an autologous bone marrow transplantation is planned.