Hodgkins lymphoma: Hodgkin lymphoma (HL) is a heterogeneous group of malignant lymphoid neoplasms of B-cell origin characterized histologically by the presence of Hodgkin and Reed-Sternberg (HRS) cells in the vast majority of cases. There are two distinct subtypes: nodular lymphocyte predominant Hodgkin lymphoma and classical Hodgkin lymphoma. Hodgkin lymphoma involves primarily lymph nodes.