[Biological characteristics and prognosis of childhood malignant lymphoma]

The biological characteristics and prognosis of childhood malignant lymphoma were reviewed. A national survey of 568 cases of childhood malignant lymphoma in Japan revealed that 505 cases (88.9%) were non-Hodgkin's lymphoma (NHL), and 63 cases (11.1%) were Hodgkin's lymphoma (HL). The biological characteristics of NHL in Japan were a male predominance, an average age of 7.8 years, and frequent occurrence in the head and neck (38.2%). Histopathologically, only 3.2% of NHL was nodular type and 96.8% was diffuse type (lymphoblastic 28.4%, histiocytic 19.5%, medium-size cell 18.6%, Burkitt's 14.6%, and miscellaneous 15.8%.) The characteristics of the 63 cases of HL were a male predominance, an average age of 9.3 years, 73% of primary lesions in the cervical nodes, and 46.6% of mixed cellularity type. The survival rate at 7 years estimated by the Kaplan -Meier method was 41.1% for patients with NHL, and 84.9% for patients with HL. Leukemic conversion and CNS involvement occurred in 27.9% and 22.9% of patients with NHL, respectively. The current multi-institutional treatment study for NHL conducted by the Children's Cancer and Leukemia Study Group (CCLSG) has improved the prognosis of childhood NHL to an 84.6% induction rate with initial therapy and a relapse-free survival rate of 55.6% at four years. The most important principle for the management of childhood malignant lymphoma is the recognition of the systemic nature of the disease.