The Relationship of Cell Morphology to CNS Involvement in Adult Leukaemia and Lymphoma

It was established over ten years ago that children dying of acute lymphoblastic leukaemia (ALL) had a high incidence of CNS infiltration, especially of the leptomeninges (Hyman et al., 1965; Thomas, 1965). Increasingly effective chemotherapy protocols resulted in the majority of children achieving remission and an increased expectation of prolonged remission duration and survival, but with an apparent increase in the cumulative risk of developing CNS leukaemia (CNSL) (Evans et al., 1970; Hustu et al., 1973; Nies et al., 1965a; Pavlovsky et al., 1973; Pinkel et al., 1971; Rieselbach et al., 1963; West et al., 1972). A greater awareness of CNSL led to improved methods of processing cerebrospinal fluid (CSF), notably membrane filtration (Del Vecchio et al., 1959; Hutton, 1958), gravity sedimentation (Kolar and Zeman, 1968; Sayk, 1960; Somas, 1967) and cytocentrifugation (Watson, 1966). These techniques clearly showed that examination of CSF cytology was capable of detecting CNSL in the absence of symptoms, clinical signs, changes in biochemistry or increased CSF cell count (Drewinko et al., 1973; Evans, 1974; Hustu et al., 1973; Nies et al., 1965b).