Granulocytic sarcoma (GS) is a form of extramedullary leukaemia (EML). The
presence of the neural cell adhesion molecule (NCAM) on the surface of the
blasts, which is recognized by the CD56 monoclonal antibody, enhances their
propensity for tissue penetration. GS within the central nervous system (C
NS), in particular within the cerebellum, is extremely uncommon. We review
the literature and describe an infant with isolated cerebellar GS relapse,
which antedated a CD56 + acute monoblastic leukaemia bone marrow (BM) relap
se. (C) 2001 Elsevier Science Ltd. All rights reserved.