{'fraction_non_alphanumeric': 0.023846153846153847, 'fraction_numerical': 0.009230769230769232, 'mean_word_length': 6.608187134502924, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
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.