The accurate diagnosis of malignant tumor type is essential to determine the correct therapeutic regimen and to predict a patient's prognosis. However, the differential diagnosis of "small-round-cell tumors", represented by neuroblastoma, rhabdomyosarcoma, leukemia/lymphoma and Ewing's sarcoma, can occasionally be difficult by conventional and biochemical methods. If monoclonal antibodies which would react with these tumor cell surface antigens were available, a membrane phenotype determined by these monoclonal antibodies could provide rapid and accurate diagnostic aids. In the present study, a panel of 9 monoclonal antibodies raised against hematopoietic cells (BA-1, BA-2, J-5 and B7/21), brain cells (UJ-13A, UJ-127-11 and anti-Thy-1), and neuroblastoma cells (HSAN1. 2 and PI 153/3) was used to analyze 7 fresh bone marrow tumor cell specimens: 6 neuroblastoma and 1 non-Hodgkin lymphoma. A rapid (within 2 hours) and confident diagnosis of each tumor type could be made on the basis of the membrane phenotype study.
