LAUSR

This paper published in 1989 comes number 8 in the most cited papers in the Journal of Clinical Pathology in this 70th anniversary of the Journal and cited some 631 times in the 27 years since it was published. In this paper, the French–American–British (FAB) group studied specimens from 110 patients who were well characterised with clinical and laboratory studies including electron microscopy.1 They looked at peripheral blood films, bone aspirate and trephine specimens and some lymph node biopsy specimens. On the basis of cytology and membrane phenotype, the disorders were defined. Immunological techniques used included distinguishing between B and T lymphocytes using membrane (SMIg) and cytoplasmic (CyIg) immunoglobulin and rosette tests with sheep erythrocytes and monoclonals against cell surface epitopes. In a series of meetings over 18 months, the group met and reviewed and discussed the cases and agreed on the classification. The technologies used were the state-of-the-art methods of the time. Morphology, the long-standing foundation of haematology, is the initial technique used. However, it is recognised that morphological appearances in certain entities can be highly variable. In this paper, the experts agree and define the appearances of the different types of chronic leukaemias and in the illustrations give clear examples of the morphology. However, at the time of …