Nodular lymphocyte predominant Hodgkin lymphoma: Clincopathological study of 25 cases from Japan with a reappraisal of tissue associated macrophages

Clinicopathological features of 25 nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) patients in Japan were analysed. To investigate the clinicopathological significance of tissue associated macrophages (TAM) in NLPHL, CD68 and CD163 expression were investigated. The median age at onset was 56 years (range: 6-82 years) with male predominance (64%). All patients presented with lymph node enlargement with predilection for cervical LNs. Seven cases (28%) had mediastinal lesion and four (16%) had extranodal involvement. Most cases (76%) presented with early clinical stages. After median follow up of 44 months, both of overall and progression free survival rates were 95%. The presence of >5% CD68+ TAM in NLPHL was significantly associated with older age at diagnosis (median, 71 vs 52.5 years; P=0.048), lower hemoglobin level (33.3% vs 0%; P=0.037) and lower CR rate after initial treatment (42.9% vs 91.7%; P=0.038). The presence of >5% CD163+ TAM was significantly correlated with presence of B symptoms (40% vs 0%; P=0.036). In conclusion, NLPHL is rare among Japanese and appears to present at an older age than among Western patients. In our series, the presence of >5% CD68+ TAM in NLPHL was associated with lower CR rate, but with no impact on patients' survival.