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The paper presents new molecular data, the principles of the classification of myeloid neoplasms, and criteria for their diagnosis according to the new edition of the WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues, 2017. Current concepts of clonal hematopoiesis and models of clonal evolution are presented to characterize the common features of the molecular pathogenesis of myeloid neoplasms. There are new data and general principles of diagnosis of myeloid neoplasms: Ph-negative myeloproliferative diseases, myelodysplastic syndromes, myeloid/lymphoid neoplasms with eosinophilia and rearrangements of PDGFRA, PDGFRB, FGFR1, and PCM1-JAK2, diseases from the group of myelodysplastic/myeloproliferative diseases. Emphasis is laid on the possibilities and limitations of pathological differential diagnosis when a pathologist examines bone marrow trepanobiopsy specimens in his/her routine work.

Development of bladder cancer (BC) involves accumulating several genetic alterations in somatic cells: point mutations, extended deletions in the localization of tumor suppressor genes, amplification of oncogenes, aberrant DNA methylation, changes in the expression pattern of regulatory RNAs and numerous structural genes. From all of the above, point mutations have the greatest potential as diagnostic markers, as they frequently occur in carcinogenesis, characterize initiation and further clonal evolution of malignancy and represent a change in DNA detectable by routine molecular genetic methods. If we look at the clinical classification of bladder cancer, 90% of the BC presented by urothelial carcinoma, 80% of patients had superficial and 20% - of muscle-invasive tumors. The differences in morphological classification, staging and prognosis of bladder cancer represent different pathogenic pathways of tumor development. Superficial bladder cancer develops through a stage of hyperplasia involving activation of mutations in the genes FGFR3, PIK3CA, HRAS, ERBB2, TERT and others. It is shown that frequent point mutations FGFR3, PIK3CA and TERT are present in the tumor cells in the urine sediment and can be considered as markers for non-invasive molecular genetic diagnosis of primary BC and for monitoring of disease recurrence. Muscle-invasive bladder cancer develops through the stages of dysplasia and carcinoma in situ, in which mutations initially occur in key suppressor genes (TP53 and RB1) and a number of chromatin remodeling genes. This leads to genomic instability and multiple chromosome aberrations that are subjected to selection in the further clonal evolution of tumors towards predominance of more malignant subclones. This review presents systematized information about the main mutations in BC carcinogenesis, their role in the primary tumor progression, metastasizing and role as a target for diagnosis and targeted therapy.

Progression of malignant tumors is largely due to clonal evolution of the primary tumor, clones acquiring different sets of molecular genetic lesions. Lesions can confer a selective advantage in proliferation rate or metastasis on the tumor cell population, especially if developing resistance to anticancer therapy. Prostate cancer (PCa) provides an illustrative example of clinically significant clonal evolution. The review considers the genetic alterations that occur in primary PCa and the mechanism whereby hormone-refractory PCa develops on hormone therapy, including mutations and alternative splicing of the androgen receptor gene (AR) and intratumoral androgen synthesis. Certain molecular genetic lesions determine resistance to new generation inhibitors (AR mutations that block the antagonist effect or allow other hormones to activate the receptor) or lead to neuroendocrine differentiation (repression of the AR signaling pathway, TP53 mutations, and amplification of the AURKA or MYCN oncogene). Multistep therapy based on the data about somatic mutations associated with progression and metastasis of the primary tumor can be expected to significantly improve the survival of patients with advanced PCa in the nearest future.