Gianelli, Umberto

ABSTRACT This study aimed to distinguish between essential thrombocythemia (ET) and prefibrotic primary myelofibrosis (pre‐PMF) using routine blood tests, with a focus on white blood cell (WBC) and platelet (PLT) levels. We evaluated the predicted probability of a pre‐PMF diagnosis based on the interaction between WBC and PLT levels using data from a logistic regression model involving 891 patients with ET and 180 patients with pre‐PMF. Patients were divided into four groups based on whether their WBC and PLT values were below or above the respective thresholds of 8.85 × 10 9 /L and 793 × 10 9 /L. The results showed that patients with low levels of both WBCs and PLTs had the lowest predicted probability of pre‐PMF (6%), indicating a profile more typical of ET. When either WBC or PLT levels were elevated, the probability increased to approximately 18%–19%, indicating a potential shift toward pre‐PMF features. Notably, patients with elevated levels of both WBCs and PLTs had the highest probability of a pre‐PMF diagnosis (26%), which was more than four times higher than that of the low–low group. The association between combined WBC/PLT levels and a pre‐PMF diagnosis remained significant ( p < 0.001), even when adjusting for serum lactate dehydrogenase (LDH) and splenomegaly. These findings suggest that elevated WBC and PLT levels together can serve as a practical and accessible diagnostic tool for supporting the differential diagnosis of ET or pre‐PMF in cases of uncertainty, and for deferring bone marrow biopsy in cases of early disease presenting with isolated thrombocytosis.

AbstractA group of international experts, including hematopathologists, oncologists, and geneticists were recently summoned (September 2021, Chicago, IL, USA) to update the 2016/17 World Health Organization classification system for hematopoietic tumors. After careful deliberation, the group introduced the new International Consensus Classification (ICC) for Myeloid Neoplasms and Acute Leukemias. This current in‐depth review focuses on the ICC‐2022 category of JAK2 mutation‐prevalent myeloproliferative neoplasms (MPNs): essential thrombocythemia, polycythemia vera, primary myelofibrosis, and MPN, unclassifiable. The ICC MPN subcommittee chose to preserve the primary role of bone marrow morphology in disease classification and diagnostics, while also acknowledging the complementary role of genetic markers for establishing clonality, facilitating MPN subtype designation, and disease prognostication.

Abstract The classification of myeloid neoplasms and acute leukemias was last updated in 2016 within a collaboration between the World Health Organization (WHO), the Society for Hematopathology, and the European Association for Haematopathology. This collaboration was primarily based on input from a clinical advisory committees (CACs) composed of pathologists, hematologists, oncologists, geneticists, and bioinformaticians from around the world. The recent advances in our understanding of the biology of hematologic malignancies, the experience with the use of the 2016 WHO classification in clinical practice, and the results of clinical trials have indicated the need for further revising and updating the classification. As a continuation of this CAC-based process, the authors, a group with expertise in the clinical, pathologic, and genetic aspects of these disorders, developed the International Consensus Classification (ICC) of myeloid neoplasms and acute leukemias. Using a multiparameter approach, the main objective of the consensus process was the definition of real disease entities, including the introduction of new entities and refined criteria for existing diagnostic categories, based on accumulated data. The ICC is aimed at facilitating diagnosis and prognostication of these neoplasms, improving treatment of affected patients, and allowing the design of innovative clinical trials.