Introduction Leukaemia is the most common form of childhood cancer, accounting for about one-third of new cases. Apart from chronic lymphocytic leukaemia, which is rare in children, the same varieties are found as in adults. Acute lymphoblastic leukaemia (ALL) accounts for 80% and acute myeloid leukaemia (AML) for 15%; chronic myelocytic and lymphocytic leukaemia is more common in adults. 1 The general clinical features of the leukaemias are similar, since all involve severe disruption of bone marrow function. Specific clinical and laboratory fea- tures differ, however, and there are considerable differ- ences in their responses to therapy and in their prognoses. With recent advances in treatment and prolonged survival, the frequency of neurological complications has increased [1]. Leukaemic complications are caused by the primary disease or the therapy. Primary effects of the disease on the central nervous system (CNS) include involvement of the leptomeninges, brain parenchyma and intracranial vessels. Granulocytic sarcoma (chloro- ma) is an uncommon manifestation of myelogenous leukaemias (3–8%) in which masses of immature myeloid cells of granulocytic lineage infiltrate bone and soft L. Porto M. Kieslich D. Schwabe F. E. Zanella H. Lanfermann Granulocytic sarcoma in children Received: 6 June 2003 Accepted: 2 October 2003 Published online: 20 April 2004 Ó Springer-Verlag 2004 Abstract We report three children with leukaemia (two acute myeloid and one acute lymphoblastic) and granulocytic sarcoma in the skull, orbit and sinuses. Lesions in these sites in children, with or without bone changes, are suggestive of systemic diseases such as lympho- proliferative conditions. Although involvement by granulocytic sarcoma, with or without acute myeloid leukaemia, is described, an association with acute lymphoblas- tic leukaemia is rare. Recognition of this rare entity is important, because early aggressive chemo- therapy can bring about regression of the tumour and improve survival. Keywords Children Æ Leukaemia Æ Central nervous system Neuroradiology (2004) 46: 374–377 DOI 10.1007/s00234-003-1127-5 PAEDIATRIC NEURORADIOLOGY L. Porto (&) Æ F. E. Zanella H. Lanfermann Institut fu¨r Neuroradiologie, Klinikum der Johann Wolfgang Goethe-Universita¨t, Schleusenweg 2–16, 60528 Frankfurt am Main, Germany E-mail: Stalmann.Porto@t-online.de Tel.: +49-69-63015462 Fax: +49-69-63017176 M. Kieslich Paediatric Neurology, Klinikum der Johann Wolfgang Goethe-Universita¨t, Schleusenweg 2–16, 69528 Frankfurt am Main, Germany D. Schwabe Paediatric Haematology and Oncology, Klinikum der Johann Wolfgang Goethe-Universita¨t, Schleusenweg 2–16, 60528 Frankfurt am Main, Germany