Systemic mastocytosis with associated myeloproliferative disease and precursor B lymphoblastic leukaemia with t(13;13)(q12;q22) involving FLT3
- A Tzankov1,
- K Sotlar2,
- D Muhlematter3,
- A Theocharides4,
- P Went1,
- M Jotterand3,
- H-P Horny5,
- S Dirnhofer1
- 1Institute of Pathology, University of Basel, Switzerland
- 2Institute of Pathology, University of München, Germany
- 3Institute of Medical Genetics, University of Lausanne, Switzerland
- 4Department of Hematology, University of Basel, Switzerland
- 5Institute of Pathology, Ansbach, Germany
- Dr A Tzankov, University Hospital Basel, Institute of Pathology, Schoenbeinstr. 40, CH-4031 Basel, Switzerland; atzankov{at}uhbs.ch
- Accepted 22 May 2008
Abstract
Systemic mastocytoses represent neoplastic proliferations of mast cells. In about 20% of cases systemic mastocytoses are accompanied by clonal haematopoietic non-mast cell-lineage disorders, most commonly myeloid neoplasms. A case of systemic mastocytosis carrying the characteristic mutation at codon 816 (D816V) in the KIT gene of mast cells, with two concurrent accompanying clonal haematopoietic non-mast cell-lineage disorders, chronic myeloproliferative disease, unclassifiable and precursor B lymphoblastic leukaemia is documented. Both accompanying clonal haematopoietic non-mast cell-lineage disorders carried the wild-type KIT gene, but had a novel t(13;13)(q12;q22) involving the FLT3 locus at 13q12. The chronic myeloproliferative disease, unclassifiable and the precursor B lymphoblastic leukaemia were cured by syngenous stem cell transplantation, but the systemic mastocytosis persisted for more than 10 years. The additional impact of molecular techniques on the correct diagnosis in haematological malignancies is highlighted, and evidence is provided that, apart from internal tandem duplications and mutations, FLT3 can be activated by translocations.
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Competing interests: None.
