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

BACKGROUND: 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).

PATIENTS AND METHOD: We investigated different morphologic patterns, CD30 and IgD expression in pediatric patients with NLPBL diagnosed at the Children's Cancer Hospital Egypt.

RESULTS: 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.

CONCLUSION: 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.