Leukemic lymphadenopathy: diagnosis by fine needle aspiration.

We report cytologic findings in 6 patients (2 with a history of chronic myelogenous leukemia and 2 with a history of acute lymphoblastic leukemia) who presented with generalized or localized lymphadenopathy of undetermined etiology. Fine needle aspiration of enlarged lymph nodes resulted in the initial diagnosis of leukemia (1 case) or blast crisis of leukemia (2 cases), confirmation of involvement by leukemia at presentation (1 case), or confirmation of relapse of leukemia (2 cases). The average number of cells in the aspirates was 20 million, sufficient for performing immunophenotypic studies, flow cytometry, cytogenetic studies, and electron microscopy. The cytological features, combined with the ancillary studies, resulted in the diagnosis and subclassification of the leukemias as follows: chronic myelogenous leukemia, blast crisis (lymphoid); chronic myelogenous leukemia, blast crisis (undifferentiated); common acute lymphoblastic leukemia; acute lymphoblastic leukemia (T-cell), acute lymphoblastic leukemia (T-cell); and malignant lymphoma, small lymphocytic type.