A small cluster of Hodgkin's disease.

Nine cases of Hodgkin's disease and one of acute lymphoblastic leukaemia occurred in 1972-5 in an area of less than 1 km. Clinical, social, and drug histories provided no relevant information, and definite patient-to-patient contacts before the onset of disease were not established. There was a higher incidence of malignant neoplasms in first-degree relatives of the patients than in those of a small control group living in the same area. There was no apparent reason for this cluster of cases, but geographical, climatic, and entomological studies are being carried out.