Synchronous FIP1L1–PDGFRA-positive chronic eosinophilic leukemia and T-cell lymphoblastic lymphoma: a bilineal clonal malignancy
Several reports of successful empirical treatment of idiopathic hypereosinophilic syndrome with imatinib led to the recent identification of the FIP1L1–PDGFRA fusion gene rearrangement, which characterizes a distinctive group of chronic eosinophilic leukemias. This fusion gene can be detected in eosinophils, neutrophils, mast cells, T cells, B cells and monocytes in FIP1L1–PDGFRA-positive hypereosinophilic patients suggesting a multilineage involvement. Furthermore, the same FIP1L1–PDGFRA rearrangement was identified in patients with hypereosinophilia and atypical mast cell proliferations, raising the question of a disease with two concomitant lines of differentiation. In addition, a recent report noted two cases with the association of FIP1L1–PDGFRA-positive chronic eosinophilic leukemia and T-cell lymphoblastic lymphoma (T-LBL). We report here the only third case of synchronous chronic eosinophilic leukemia and T-LBL, both associated with a FIP1L1–PDGFRA fusion transcript, confirming the occurrence of such disease and suggesting a clonal proliferation with two lines of differentiation probably arising from a primitive multipotent medullary stem cell.
Document Type: Research Article
Affiliations: 1: Department of Pathology, Université Paris 13 2: Department of Haematology, Hôpital Saint-Louis, Université Paris 7 3: Department of Haematology, Hôpital Kremlin-Bicêtre Université Paris 11 4: Department of Clinical Haematology, Hôpital Avicenne, Université Paris 13 5: Department of Haematology, Hôpital Avicenne, Université Paris 13, Assistance Publique–Hôpitaux de Paris, Paris, France
Publication date: January 1, 2008