Cytogenetic and molecular evidence of marrow involvement in extramedullary acute myeloid leukaemia.
A diagnosis of granulocytic sarcoma was made in a 2-year-old child based on the detection of myelomonocytic blasts in tissue obtained from a subcutaneous nodule with no evidence of concomitant disease in the bone marrow. The child responded to systemic chemotherapy and is in remission 3 years later. An identical clone with an in frame fusion of the MLL and AF10 genes was identified from both tissue and bone marrow samples. The generation of an in frame MLL-AF10 fusion requires complex intra- and interchromosomal exchanges between chromosomes 10 and 11. In this case, an intrachromosomal rearrangement of chromosome 5 was also observed. This case illustrates the presence of systemic disease in extramedullary leukaemia, its response to systemic rather than topical therapy and suggests that the events leading to chromosomal translocations in leukaemia may be part of a generalized intracellular event.
Lillington
D M
DM
Department of Medical Oncology, The Imperial Cancer Research Fund, St Bartholomew's and the Royal London School of Medicine and Dentistry, London, UK.
Jaju
R J
RJ
Shankar
A G
AG
Neat
M
M
Kearney
L
L
Young
B D
BD
Saha
V
V
D000208:Acute Disease; D019677:Artificial Gene Fusion; D001854:Bone Marrow Cells; D002895:Chromosomes, Human, Pair 5; D004268:DNA-Binding Proteins / Q000235:genetics; D004587:Electrophoresis, Agar Gel; D005260:Female; D015321:Gene Rearrangement; D011495:Histone-Lysine N-Methyltransferase; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D007621:Karyotyping; D007951:Leukemia, Myeloid / Q000235:genetics*; D051788:Myeloid-Lymphoid Leukemia Protein; D011519:Proto-Oncogenes; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics
D004268:DNA-Binding Proteins; C497422:KMT2A protein, human; C092513:MLLT10 protein, human; D014157:Transcription Factors; D051788:Myeloid-Lymphoid Leukemia Protein; D011495:Histone-Lysine N-Methyltransferase