Early and reliable diagnosis of non-Hodgkin lymphoma in childhood and adolescence: contribution of cytomorphology and flow cytometric immunophenotyping.

Non-Hodgkin lymphoma (NHL) represents one of the most rapidly growing malignancies in childhood and adolescence. About 80% of patients now are cured with adequate treatment. Serious complications at presentation due to tumor lysis syndrome or local tumor effects are commonly observed. Thus, a rapid diagnosis with the least invasive procedure enabling the initiation of early and specific therapy is necessary to diminish early fatality or persistent impairment. In 56 centrally registered patients with NHL, cytomorphologic analyses (FAB criteria) of May-Grünwald-Giemsa-stained touch imprints or malignant effusions and flow cytometric immunophenotyping (EGIL criteria) of fresh cell suspensions with a standardized panel of monoclonal antibodies were performed. The authors identified 23 patients with Burkitt lymphoma by the combination of FAB L3 morphology and a mature B-cell phenotype and 22 patients with lymphoblastic lymphoma by FAB L1/L2 morphology and a T-/B-cell precursor phenotype. They also found 11 patients with large cell lymphomas, 3 of them with anaplastic large cell lymphoma (T-cell phenotype; NPM/ALK-positive). In the remaining 8 patients diffuse large B-cell lymphoma was suspected by the combined use of cytologic and immunophenotypic findings (mature B-cell phenotype). In all cases with available solid tumor material (n = 42/56) the preliminary diagnosis was confirmed by histopathology. Burkitt lymphoma, lymphoblastic lymphoma, and, in a few cases, some large cell lymphomas could be classified reliably by cytomorphology and immunophenotyping of freshly obtained tumor cell material, enabling an early start of specific lymphoma treatment.