Immunocytochemistry in fine needle aspirates of small cell-, round-, blue-cell malignant tumors of childhood (neuroblastoma, nephroblastoma, lymphoma, Ewing's sarcoma, rhabdomyosarcoma).

Immunocytochemistry with the use of monoclonal antibodies to vimentin, keratin, desmin, neurofilaments and leukocyte common antigen (LCA) was applied to 53 fine needle aspirates of small cell-, round-, blue-cell malignant tumors of childhood (neuroblastomas, nephroblastomas, non-Hodgkin's lymphomas, Ewing's sarcomas and rhabdomyosarcomas). The results revealed the following immunophenotypes: neuroblastomas were positive for neurofilaments. Nephroblastomas contained vimentin (in blastema cells), keratin (in epithelial and blastema cells) Non-Hodgkin's lymphomas were vimentin and LCA positive, keratin negative. Ewing's sarcomas displayed multidirectional differentiation. Rhabdomyosarcomas were desmin and vimentin positive. It is concluded that immunocytochemistry in fine needle aspirates should be used as an objective evidence to support morphologic differential diagnosis of small cell-, round-, blue cell malignant tumors of childhood.