Biology, clinical course and management of nodular lymphocyte-predominant hodgkin lymphoma.

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) differs in histological and clinical presentation from classical Hodgkin lymphoma (cHL). The typical morphologic signs of NLPHL are atypical "lymphocytic and histiocytic" (L&H) cells, which are surrounded by a non-neoplastic nodular background of small lymphocytes of B-cell origin. The NLPHL cells are positive for CD45, CD19, CD20, CD22 and CD79a, but lack expression of CD15 and CD30, the typical markers for cHL. NLPHL patients are predominantly of male gender with a median age of 37 years. Patients often present in early stages (63%) and rarely have B-symptoms (9%). Treatment of NLPHL patients using standard Hodgkin lymphoma (HL) protocols leads to complete remission (CR) in more than 95% of patients. Survival and freedom from treatment failure (FFTF) are worse in advanced-stage patients than in early-stage patients. Thus, patients in advanced and in early stages with unfavorable risk factors are treated similarly to cHL patients. In contrast, patients with early-stage NLPHL without risk factors can be sufficiently treated with reduced intensity programs having less severe adverse effects. As a result, treatment of early NLPHL is less clearly defined, including radiotherapy in extended field (EF) or involved field (IF) technique, combined modality treatment, and, more recently, monoclonal antibody rituximab. Watch and wait strategy plays an important role in pediatric oncology to avoid adverse effects associated with therapy.