Onkológia 6/2019
Systemic mastocytosis – diagnostics and perspectives of therapy
Mastocystosis is a group of rare clonal diseases characterised by abnormal expansion and accumulation of neoplatic mast cells (MC) in different tissues. Isolated infiltration of the skin is called cutaneous mastocytosis (CM), infiltration of other organs is systemic mastocytosis (SM). According to WHO classification, SM can have three variants: indolent (ISM), smoldering (SSM) and a group of advanced SM (AdvSM), i.e. agressive SM (ASM), SM associated with hematological neoplasia (SM-AHN) and mast cell leukemia (MCL). In pathogenesis of mastocytosis, mutation KIT D816V plays an important role, and prevalence of this mutation is about 95% in patients with AdvSM. Clinical manifestation and symptoms are caused by mediators released from activated mastocytes and by organ impairment based on their infiltration by mast cells. Most impressive are skin changes called urticaria pigmentosa. In diagnostic process, bone marrow and skin biopsy play a key role, where finding of multifocal aggregates of morphologically abnormal mast mast cells is maior criterion. Treatment of all variants is focused on therapy of symptoms caused by released mediators, but in cases of AdvSM, cytoreductive therapy determines prognosis. Conventional therapy are interferon-alpha and cladribin. Several thyrosinkinase inhibitors (TKI) are in clinical studies, but the only one effective and already available, is midostaurin. Mastocytosis is definitely curable only by allogenic stem cell transplantation (AlloSCT).
Keywords: mast cells, systemic mastocytosis, KIT mutation, tryptase, midostaurin
