Central nervous system leukaemia in children

Abstract

Infiltration of the nervous system is the most common extramedullary manifestation of acute leukaemia in childhood. Of 28 children with acute lymphoblastic leukaemia (ALL) diagnosed between 1964 and 1969 and followed regularly thereafter, 21 (75%) developed neurological leukaemia. The first episodes occurred between 20 days and 27 mth. from diagnosis, but 64% of all cases of leukaemia and 86% of all patients destined to develop neurological leukaemia had evidence of infiltration by 15 mth. from diagnosis. The common features of the initial episode were headaches (10), vomiting (13), drowsiness (9), mood changes (10), cranial nerve palsies (8), spinal or peripheral nerve involvement (l), papilloedema (14), raised CSF pressure (10/17), CSF pleocytosis (17/20), elevated CSF protein above 40 mg./100 ml. (8/17), and CSF glucose levels below 35 mg./l00 ml. (5/16). The initial complication occurred during haematological remission in 11, during frank relapse in 8, during partial control in 1, and during the remission induction phase in one patient. The 21 patients suffered from neurological leukaemia on 82 occasions, the greatest number being 13 episodes in one child. On 74 occasions there was evidence of brain and or meningeal (CNS) involvement, on 4 occasions spinal or peripheral nerve infiltration, and in 4 patients a combination was present. Six of the children had a prolonged survival of from 3-5yr. 11 mth., and the longest survivor remains in continuous haematological remission. The six children who did not develop neurological leukaemia survived from 18 to 86 mth., 3 being still alive at 34, 63 and 68 mth. from diagnosis. Of 18 patients with ALL diagnosed between January 1970 and June 1971, 4 have already developed CNS leukaemia at intervals of 4½ to 12 mth. from diagnosis. As only 3 have been followed for more than 15 mth., the incidence of neurological leukaemia is likely to increase. In view of the extremely high incidence of neurological infiltration in acute lymphoblastic leukaemia, prophylactic treatment with intrathecal methotrexate and radiotherapy soon after diagnosis appears warranted.