The diagnosis and management of hairy-cell leukaemia.

Over a 4-year period 203 patients with various types of leukaemia were treated by the Haematology Unit at the Johannesburg Hospital. Ten of them were suffering from the condition known as hairy-cell leukaemia or leukaemic reticulo-endotheliosis. They were all men, and ranged in age from 29 to 67 years (mean 56 years). The majority presented with pancytopenia, and there was invariably splenomegaly, while lymphadenopathy was rare. Hairy cells were identified microscopically in the peripheral blood of 7 patients and in 5 the specific cytochemical marker, tartrate-resistant acid phosphatase, was present. In addition, in a further 2 patients this feature, which was not identified in the peripheral blood, was found in the splenic cells. The bone marrow trephine biopsy specimens characteristically showed extensive lymphoid infiltration associated with a dense disordered deposition of reticulin fibres. Electron microscopical and immunological studies proved to be of doubtful diagnostic value. Splenectomy was carried out on 9 patients, and there was tumour involvement in all the spleens removed. Two patients died from septicaemia, the one before splenectomy and the other 9 months after the operation. The 8 remaining patients have had their subjective symptoms alleviated and their peripheral blood indices have been improved by splenectomy, and none has required further treatment for periods now ranging from 7 to 41 months.