Molecular and virologic characteristics of lymphoid malignancies in children with AIDS

Purpose: To characterize AIDS-associated lymphoid malignancies in children. Patients and Methods: We studied lymphomas and B-cell leukemias from 25 chi ldren with AIDS for immunoglobulin heavy chain gene clonality, c-myc oncoge ne abnormalities, and presence of HIV and Epstein-Barr virus. Results: Monoclonal immunoglobulin gene rearrangements were identified in 2 2 of 23 cases tested, the single exception being one of mucosa-associated l ymphoid tissue. Immunoglobulin gene/c-myc translocations were found in 3 of 4 cases of B (surface immunoglobulin-positive)-acute lymphoblastic leukemi a, 8 of 11 small noncleaved cell lymphomas, and 1 of 5 large cell lymphomas . Mutations of c-myc were found in 2 of 13 small noncleaved cell lymphomas, 1 of 2 Epstein-Barr virus-positive mucosa-associated lymphoid tissue neopl asms, and 1 of 4 Epstein-Barr virus-negative B-acute lymphoblastic leukemia . Six small noncleaved cell lymphomas, both mucosa-associated lymphoid tiss ue neoplasms and one of large cell lymphoma had high levels of Epstein-Barr virus in tumor tissue. Hodgkin's disease tissue and B-acute lymphoblastic leukemia tumors were negative for EBV. Proviral HIV-1 was not detected in a ny tumor. Conclusions: AIDS-associated lymphoid malignancies in children appear to ha ve a different distribution of histologic subtypes than adult HN-infected i ndividuals, fewer large cell lymphomas occur in children. The small nonclea ved cell lymphomas exhibit a lower frequency as well as different locations of c-myc mutations than AIDS-associated small noncleaved cell lymphomas in adults.