title: Synchronous FIP1L1-PDGFRA-positive chronic eosinophilic leukemia and T-cell lymphoblastic lymphoma: a bilineal clonal malignancy.
abstract: 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.
authors.affiliation: Department of Pathology, Université Paris 13, Paris, France. mat_cap@caramail.com
authors.forename: Mathieu
authors.initials: M
authors.lastname: Capovilla
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Cayuela
authors.forename: Chrystèle
authors.initials: C
authors.lastname: Bilhou-Nabera
authors.forename: Claude
authors.initials: C
authors.lastname: Gardin
authors.forename: Remi
authors.initials: R
authors.lastname: Letestu
authors.forename: Fanny
authors.initials: F
authors.lastname: Baran-Marzak
authors.forename: Pierre
authors.initials: P
authors.lastname: Fenaux
authors.forename: Antoine
authors.initials: A
authors.lastname: Martin
mesh_terms: D000328:Adult; D019070:Cell Lineage; D002999:Clone Cells; D006801:Humans; D017681:Hypereosinophilic Syndrome / Q000209:etiology / Q000473:pathology*; D016399:Lymphoma, T-Cell / Q000209:etiology / Q000473:pathology*; D008297:Male; D015514:Oncogene Proteins, Fusion / Q000032:analysis* / Q000235:genetics; D012333:RNA, Messenger; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000032:analysis* / Q000235:genetics; D039221:mRNA Cleavage and Polyadenylation Factors / Q000032:analysis* / Q000235:genetics
chemical_list: C479818:FIP1L1 protein, human; D015514:Oncogene Proteins, Fusion; D012333:RNA, Messenger; D039221:mRNA Cleavage and Polyadenylation Factors; C479819:FIP1L1-PDGFRA fusion protein, human; D020796:Receptor, Platelet-Derived Growth Factor alpha