Pediatric lymphomas in Brazil

ABSTRACT

OBJECTIVE: This study provides the clinical pathological characteristics of 1301 cases of pediatric/adolescent lymphomas in patients from different geographic regions of Brazil. METHODS: A retrospective analyses of diagnosed pediatric lymphoma cases in a 10-year period was performed. We believe that it represents the largest series of pediatric lymphomas presented from Brazil. RESULTS: Non-Hodgkin lymphomas represented 68 percent of the cases, including those of precursor (36 percent) and mature (64 percent) cell origin. Mature cell lymphomas comprised 81 percent of the B-cell phenotype and 19 percent of the T-cell phenotype. Hodgkin lymphomas represented 32 percent of all cases, including 87 percent of the classical type and 13 percent of nodular lymphocyte predominant type. The geographic distribution showed 38.4 percent of the cases in the Southeast region, 28.7 percent in the Northeast, 16.1 percent in the South, 8.8 percent in the North, and 8 percent in the Central-west region. The distribution by age groups was 15-18 years old, 33 percent; 11-14 years old, 26 percent; 6-10 years old, 24 percent; and 6 years old or younger, 17 percent. Among mature B-cell lymphomas, most of the cases were Burkitt lymphomas (65 percent), followed by diffuse large B-cell lymphomas (24 percent). In the mature T-cell group, anaplastic large cell lymphoma, ALK-positive was the most prevalent (57 percent), followed by peripheral T-cell lymphoma, then not otherwise specified (25 percent). In the group of classic Hodgkin lymphomas, the main histological subtype was nodular sclerosis (76 percent). Nodular lymphocyte predominance occurred more frequently than in other series. CONCLUSION: Some of the results found in this study may reflect the heterogeneous socioeconomical status and environmental factors of the Brazilian population in different regions.