Untangling Systemic Mastocytosis: An Update on Challenges in the Diagnosis and Treatment of Myeloid Neoplasms with Systemic Mastocytosis

This symposium was held on the first day of the 2023 European Hematology Association (EHA) Congress, held in Frankfurt, Germany. The main objective of the symposium was to gather experts from the field to raise awareness of the challenges in diagnosing and treating systemic mastocytosis (SM) with an associated haematologic neoplasm (AHN). Presentations focused on optimising the diagnosis of the SM component and recognising the different types of myeloid AHN. The expert panel considered the clinical management of SM-AHN, and how and when to prioritise the various disease components. The overarching message from the symposium was that diagnosis of SM-AHN is challenging, and SM is often missed in patients with a myeloid neoplasm, such as chronic myelomonocytic leukaemia (CMML), myelodysplastic/myeloproliferative neoplasm (MDS/MPN), myelodysplastic syndrome (MDS), and myeloproliferative neoplasm (MPN), as well as AHN being missed in patients with SM. Identification of a SM-AHN through serum tryptase and/or molecular testing for KITD816V mutation in peripheral blood in a patient with a previous diagnosis of a myeloid neoplasm allows potentially efficacious targeted treatment with KIT inhibitors, such as midostaurin and avapritinib. Although SM-AHN is associated with a poor prognosis, a correct diagnosis and detailed understanding of an individual’s disease can help to guide optimal treatment decisions, including when to prioritise SM treatment over AHN treatment, and vice versa.