Fine-needle aspiration biopsy diagnosis of small round cell tumors of childhood: A comprehensive approach

Fine-needle aspiration biopsy findings in small round cell malignant tumors of children are briefly reviewed. All of these tumors usually have charact eristic cytomorphology which, when recognized, may lead to a definitive dia gnosis. However; when these tumors are undifferentiated, morphologic criter ia may not be sufficient for arriving at a correct diagnosis. A variety of ancillary studies including electron microscopy, immunohistochemistry and D NA ploidy cytogenetics, and fluorescent in situ hybridization may provide v aluable additional information for precise characterization of these neopla sms. Some of the ancillary studies may also be used for assigning these cas es to prognostically significant subgroups. This information may also help in defining the most suitable chemotherapeutic regimens Sor these tumors. S ince most of these special studies require only a small amount of cellular material, line-needle aspiration biopsy is ideally suited for obtaining sam ples for these procedures. It is hoped that as cytogenetic and molecular te chniques become available in many diagnostic laboratories, a comprehensive evaluation of aspiration biopsies from round cell malignant tumors, encompa ssing a precise pathologic diagnosis, determination of prognosis, and predi ction of response to therapy: will be possible in a majority of cases. Diag n. Cytopathol. 1999;21,81-91. (C) 1999 Wiley-Liss, Inc.