The significance of primitive cells in marrow aspirates of children with neuroblastoma

A study was undertaken to determine the nature of primitive cells resembling lymphoblasts found in the marrow of an asymptomatic child with neuroblastoma. The cells proved to be lymphoblasts by electron microscopy and were similar in appearance to antibody-producing lymphocytes. A retrospective analysis was made of 90 marrow aspirates from 19 children with neuroblastoma. The mean percentage of lymphocytes and lymphoblasts was calculated for each patient. To determine the prognostic significance, if any, of the presence of these cells, patients were grouped according to age and stage of disease at diagnosis and to the presence or absence of disease at the time the analysis was made. Increased numbers of lymphoblasts were seen in patients with a good prognosis. Differentiation between isolated neuroblasts and cells resembling lymphoblasts is important because the presence of tumor cells is an ominous sign while lymphoblasts correlate with a good life expectancy.