Retrospective evaluation of patients with systemic mastocytosis in Hacettepe University Hospital in terms of clinical, demographic, laboratory findings and treatment. Hacettepe University Medical Faculty mastocytosis experience

Systemic mastocytosis (SM) is a clonal, neoplastic disorder which leads proliferation of morphologically and immunophenotypically abnormal mast cells that accumulate in one or more organ systems. It can be divided in subtypes with different clinics and prognoses. This study is a single-center descriptive cohort study which evaluated in terms of clinical, demographic, treatment and laboratory findings of 30 adult patients who were followed up with the diagnosis of SM according to the revised 2016 WHO diagnostic criteria in Hacettepe University Medical Faculty Hospitals between January 2001 and April 2020. The aim of this study is to raise awareness of SM and contribute to the developing literature. Fifteen patients (50%) were followed for indolent SM (ISM), 1 patient (3.3%) smouldering SM, 10 patients (33.4%) aggressive SM (ASM) and 4 patients (13.3%) SM with associated haematological neoplasia. Serum tryptase level was associated with systemic mastocytosis subtypes. ASM patients had higher triptase levels than ISM patients. Skin lesions were observed in 66.7% of patients, musculoskeletal symptoms in 78.9% and at least on episode of anaphylaxis in 36%. The most common C findings in patients followed for ASM were bone marrow failure in 6 patients (60%) and bone pathologies in 4 patients (40%). A total of 12 patients used injectable adrenaline and 13 patients used antihistamines. 9 of 10 patients with osteoporosis used bisphosphonate and one case used denosumab. There were 10 patients who received cytoreductive treatment. Three (30%) patients followed for ASM used midostaurin, one (10%) imatinib and 5 (50%) used interferon alpha. This study demonstrates that there is a broad and diverse spectrum of SM in a clinical sense, and reveals the need for a multidisciplinary approach for optimal management and early diagnosis of this disease.