Lymphocyte-rich classical Hodgkin lymphoma (LRCHL): clinico-pathological characteristics and outcome of a rare entity

Background: To investigate the proportion, clinical characteristics and outcome of lymphocyte-rich classical Hodgkin lymphoma (LRCHL) in relation to nodular lymphocyte predominant HL (NLPHL) and classical HL (cHL). Patients and methods: A series of 2743 HL patients of all stages enrolled into three EORTC trials (H7, H8, H34) conducted between 1988 and 2000 and forming an unbiased series of HL patients was studied. Results: Detailed histological classification after panel review was available in 96% of the cases to allow selection of all cases with features potentially compatible with the WHO-definition of LRCHL for this study. Cases with dominance of lymphocytic infiltrate and relative paucity of eosinophils and fibrosis could be selected for re-classification. Twenty-one (0.8%) LRCHL cases were identified of which three were originally classified as NLPHL, seven as nodular sclerosis HL (NSHL) and 11 as mixed cellularity (MCHL), indicating that LRCHL is a rare disease. Conclusions: Clinical evaluation of the unselected series of patients (n = 2743) showed that LRCHL and NLPHL cases more often presented with favorable features. Clinical outcome adjusted on ab initio patient prognosis did not differ between the three histological entities. These results strongly suggest that LRCHL corresponds to an early stage in the spectrum of cHL rather than a biologically different disease entity.