Pathomorphology of cutaneous mastocytosis; [Патоморфология мастоцитоза кожи]

Introduction. Mastocytosis as a result of mast cell infiltration of the skin and other organs develops at any age. The relevance of this work is determined by the lack of systematic data on the pathomorphological features of the clinical forms and types of cutaneous mastocytosis, defined by the Consensus European-American Mastocytosis Group and the WHO classification in 2016. The variability of dermatological clinical manifestations in children and adults, the difficulties in interpreting laboratory tests create a problem for verifying the diagnosis and further treatment. The aim. To determine the main pathohistological features of clinical forms and types of cutaneous mastocytosis. Material and methods. The article includes data from patients who were treated and monitored at the Moscow Scientific and Practical Center of Dermatovenereology and Cosmetology in 2019–2022. Results. The literature and own data on the characteristic pathomorphological patterns that are important for the diagnosis of mastocytosis with skin lesions in children and adults are systematized. The pathological substrate of lesions in diffuse cutaneous mastocytosis and mastocytoma was a massive infiltrate of mast cells in the papillary and reticular layers of the dermis. The histological picture in the monomorphic type of maculopapular cutaneous mastocytosis (MPCM) in children was characterized by a relatively lower density of mast cell infiltration of the papillary dermis compared to other clinical forms of mastocytosis. Also, in children, the density of mast cells in the affected skin was significantly higher compared to adults. In addition, in adults with PPCM, the papillary dermis was less infiltrated with mast cells. This confirms the opinion that the monomorphic type of MPCM in children is phenotypically similar to MPCM in adults. Conclusions. Further prospective follow-up of patients may allow conclusions to be drawn about the prognostic value of pathological examination in mastocytosis in adults and children. © 2022 Zhejiang Daxue Xuebao (Nongye yu Shengming Kexue Ban)/Journal of the Zhejiang University - Agriculture and Life Science. All rights reserved.