Nodular lymphocyte predominant Hodgkin lymphoma (ORPHA:86893)
Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is a rare subtype of Hodgkin lymphoma (HL; see this term) characterized histologically by malignant lymphocyte predominant (LP) cells and the absence of typical Hodgkin and Reed-Sternberg (HRS) cells.
Epidemiology
NLPHL accounts for only 5-10% of HL cases and has an annual incidence of approximately 1/ 830,000.
Clinical description
Disease onset usually occurs before the age of 40 and there is a 3:1 male predominance for the disease. Unlike classical Hodgkin lymphoma (CHL; see this term) NLPHL has a greater tendency to be restricted to peripheral lymph nodes (neck, axilla or inguino-femoral). Mediastinal involvement is rare and nodal spread is discontiguous. More than 80% of cases present with stage 1 or 2 disease. B-symptoms (fever, drenching night sweats and unexplained weight loss) are also less commonly observed and there is usually no impaired immunity in NLPHL patients. Extranodal disease is extremely uncommon in NLPHL but it can occur in the spleen (10-15% of cases), the liver (<5% of cases) and bone marrow or lungs (<5% of cases). Long-term complications include secondary malignancies (diffuse large B-cell lymphoma (25% risk by 20 years; see this term) or epithelial cancers (lung, breast, GI), which often arise from within a prior irradiated area).
Etiology
The exact cause is unknown. Unlike the Hodgkin cells and multinucleated Reed-Sternberg (HRS) cells seen in CHL, LP cells are usually negative for all EBV markers. Genetics may play a role as LP cells frequently contain rearranged immunoglobulin genes and chromosomal abnormalities are observed in two thirds of cases.
Diagnostic methods
A biopsy (usually of a lymph node) is first performed in order to diagnose NLPHL. Diagnosis is based on the presence of CD20 positive, CD15 negative and CD30 negative LP cells. LP cells are monoclonal B cells of germinal center origin. Staging (based on the Cotswold staging system) is then performed in order to determine the severity and spread of NLPHL and decide on the best course of therapy.
Differential diagnosis
Differential diagnosis includes lymphocyte-rich classical HL (see this term), progressive transformation of germinal centers and T-cell rich large B-cell lymphoma.
Management and treatment
Previously the usual treatment for limited stage 1 or 2 disease was involved-field radiation therapy (IFRT) at 30-36Gy; however; many authorities now recommend that NLPHL be treated the same as CHL. Chemotherapy or combined modality therapy is necessary in advanced disease stages. Relapses are common (seen in 10-15%) and can occur multiple times. In cases where salvage therapies used in CHL are unsuccessful, rituximab shows promise for the treatment of recurrent NLPHL as it attacks LP cells via surface CD20. Patients need to be monitored for secondary malignancies and cardiopulmonary disease as these long-term complications can arise due to therapy-related toxicity.
Prognosis
Prognosis is good with usually a 90-100% remission rate with primary therapy. Relapse is common (seen in 10-15% of patients) and occurs on average 3-6 years after diagnosis. Overall 10 year survival rates are >90% in limited stage disease.

                            Last update: 
                            October 2012


                            - Expert reviewer(s): 
                            Dr Joseph CONNORS