Molecular analysis of T-cell Acute Lymphoblastic Leukemia arising after Essential Thrombocythemia foreshadows a distinct clonal route for lymphoid blast crisis in Philadelphia-negative chronic myeloproliferative neoplasm: a case report with literary review

progression to acute myeloid leukemia is a well-known complication of classical philadelphia-negative chronic myeloproliferative neoplasms, but less frequently disease progression to Acute Lymphoblastic Leukemia has been documented too. A molecular explanation for this rare phenomenon is missing. However the clonal haematopoiesis mostly present in these patients may work as seeding soil for a second neoplastic disease. Molecular results from this case study of a secondary acute lymphoblastic leukemia presenting after Essential Thrombocythemia support this hypothesis. In this contest secondary Acute Lymphoblastic Leukemia should not be considered as a real blast crisis, but rather as a second cancer determined by a different clonal route. Given the unique features of this case, a review of the published cases of MPN transforming to acute lymphoblastic leukemia available in literature is provided in the article.