Variant histology of pediatric nodular lymphocyte-predominant Hodgkin lymphoma with IgD and CD30 expression.

Abstract

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL), recently known as nodular lymphocyte-predominant B-cell lymphoma (NLPBL), accounts for 5%-10% of Hodgkin lymphoma (HL). Different morphologic patterns of NLPBL are identified and categorized as typical patterns (type A and B) and variant histologic patterns (types C, D, E, and F). We investigated different morphologic patterns, CD30 and IgD expression in pediatric patients with NLPBL diagnosed at the Children's Cancer Hospital Egypt. Forty-six (53%) of the patients exhibited a typical histologic pattern, whereas the remaining (47%) exhibited variant histologic pattern. Variant histology is associated with unfavorable clinical characteristics, such as advanced stages, B-symptoms, and extranodal involvements, particularly bone marrow and bone infiltration, with p-values of .06, .05, and 0.01%, respectively. Additionally, 39% of patients with variant histology experienced disease progression or relapse, compared to only 15.2% of patients with typical patterns (p=.009). Types C and D are related to decreased event-free survival (EFS), as shown by a p-value of .05. The 5-year EFS for patients with variant histology was 94.4% for the rituximab, cyclophosphamide, vincristine, doxorubicin, and prednisone (RCHOP) versus 33.3% for the adriamycin, bleomycin, vinblastine, and dacarbazine (ABVD). IgD expression in lymphocyte-predominant (LP) cells was detected in 44 (50%) patients, while CD30 expression in LP cells was found in 39 (44%) patients. Variant histology of NLPBL was associated with advanced disease stages and a poor prognosis, while expression of IgD and CD30 in LP cells was not. The poor outcome of variant histology improved with the RCHOP regimen.