A malignant lymphoid neoplasm, usually arising in lymph nodes characterised by morphological heterogeneity and bizarre giant tumour cells referred to as Reed-Sternberg cells. The aetiology of Hodgkin's disease is unknown, although current epidemiological data suggest an infectious etiology. The disease has been recognised in all or several members of "close-knit" groups, usually occurring in these persons several years after they have separated from one another. As in non-Hodgkin lymphomas, there is morphological and immunological evidence to suggest a viral etiology.