Childhood malignant non-Hodgkin lymphomas of uncommon histology

Abstract

Uncommon histologies were identified in 36 of 1336 cases (2.7%) of newly diagnosed childhood non-Hodgkin lymphoma (NHL). Seventeen cases were classified as follicular (six cases as mixed small and large cell, nine as large cell, and two as small non-cleaved cell) and 19 cases as diffuse (18 cases as mixed small and large cell, and one as small cell lymphocytic). The follicular pattern group included a preponderance of male patients; the median age at diagnosis was 11.7 years. These children presented primarily with low-stage disease involving lymph nodes or tonsils. All patients except one achieved complete remission and remain disease-free for 11 months to 18.8 years (actuarial 5-year event-free survival, 94%). The group with diffuse histologies was similar in sex ratio, age at diagnosis (median = 12.1 years), and nodal involvement, but tended to have more advanced-stage disease. Moreover, only 14 of 19 (74%) children with diffuse intermediate-grade histologies are alive in continuous complete remission (actuarial 5-year event-free survival, 70%). These results suggest that follicular pattern childhood NHL has an excellent prognosis, whereas cases with diffuse intermediate-grade histology are prognostically similar to those with diffuse high-grade histologies.