Follicular (nodular) lymphoma in childhood: a rare clinical-pathological entity. Report of eight cases from four cancer centers.

Eight cases of follicular lymphoma (FL) were found amount 318 children with non-Hodgkin's lymphoma seen in two decades in four large institutions (overall incidence: 2.5%). The children's ages ranged from 3 to 13 years (median 8). Four patients presented with localized peripheral lymphadenopathy, two with tumors of the digestive tract, two with disseminated disease. Five were tentatively classified as stage I or II and 3 as stage IV. The existence of other diseases responsible for lymphadenopathy could satisfactorily be exclued. All patients are alive after follow-up periods of 1 to 14 years from diagnosis (median 4). Morphologically, 5 lymphomas were mixed and 3 histiocytic. The growth pattern was "expansile" in the younger patients (3 to 9 years), and "infiltrative," as in the adult disease, in the three older children (11 to 13 years). The histiocytic cytology correlated with stage IV disease. FL in children appears to be different from both its adult counterpart and the diffuse childhood lymphomas. Differences with the former include the absence of tumors of poorly differentiated lymphocytic type, the higher frequency of stage I-II disease and the better prognosis. This last feature, as well as the higher frequency of peripheral node involvement and the absence of leukemic conversion or CNS disease, differentiates the follicular from the diffuse childhood lymphomas.