[Modern view on the problem of diagnostics of renal angiomioadenomatous tumor].

INTRODUCTION: Angiomyoadenomatous tumor as a nosological entity is not included in the latest version of the International Histological Classification of Kidney Tumors (WHO, 2022) and is related to provisional entity. Currently, there is no consensus among researchers about the nosological affiliation of an angiomyoadenomatous tumor. AIM: To comparatively analyze the histological, immunophenotypic, ultrastructural and molecular parameters of renal angiomyoadenomatous tumor and clear cell papillary renal cell tumor. MATERIALS AND METHODS: The study was performed on surgical specimen from 5 and 10 patients with renal angiomyoadenomatous tumor and with clear cell papillary renal cell tumor, respectively. Immunohistochemical study was carried out on paraffin sections according to the standard protocol. Antibodies HMWCK, AE1/AE3, 7, E-Cadherin, EMA, PAX8 and 9 were chosen. To study tumor tissues on semi-thin and ultra-thin sections, an electron microscope Philips TECNAI 12 BioTwinD-265 was used. For in situ fluorescent diagnostic detection, defined centromere probes, LSI 13/21, LSI N25 /LSI ARSA, TelVysion telomeric probe and a two-color VHL/CEP3 probe were used. RESULTS: Angiomyoadenomatous tumor is characterized by a three-phase structure. In contrast to clear cell papillary renal cell tumor, angiomyoadenomatous tumors show complete membranous expression of CA9. CONCLUSION: Our results allow to state that angiomyoadenomatous tumor and clear cell papillary renal cell tumor are different neoplasms.

[Morphological and molecular portrait hybrid renal tumors].

A hybrid tumor is not officially included in the latest International Histological Classification of Kidney Tumors (WHO, 2022), however, according to the literature, a number of researchers still consider a hybrid tumor as an independent nosological unit. In this regard, the development of morphological and molecular genetic criteria for a hybrid tumor, today, is the main task in the differential diagnosis of oncocytic renal tumors. AIM: Our aim was to carry out to identify immunohistochemical, ultrastructural features and determine the molecular profile of hybrid renal tumors. PATIENTS AND METHODS: The study was performed on the surgical material of 12 patients with a hybrid tumor of the kidney. Immunohistochemical study was carried out on paraffin sections according to the standard protocol. Antibodies CK7, CD117, Cyclin D1, EpCAM, Caveolin1, EABA, and S100A1 were used. To study tumor tissues on semi-thin and ultra-thin sections, an electron microscope Philips TECNAI 12 BioTwinD-265 is used. For in situ fluorescent diagnostic detection, defined centromere probes, LSI 13/21, LSI N25 /LSI ARSA and TelVysion telomeric probe. RESULTS: In some cases, a hybrid tumor is represented by a solid structure of monomorphic oxyphilic cells with a characteristic immuno-, ultraphenotype and molecular profile. CONCLUSION: The results of a comprehensive study confirm that the hybrid tumor is an intermediate link in the process of malignant transformation of oncocytoma into chromophobe renal cell carcinoma.

[Modern molecular-genetic aspects of histological variants of renal cell carcinoma].

The article presents the main molecular mechanisms of the pathogenesis of renal cell carcinoma. The molecular pathways that determine the development of histological variants of renal cell carcinoma and the role of stem cells markers in the carcinogenesis of these tumors are considered.

[Ultrastructural features of histological variants of renal cell carcinoma].

The article presents the main electron microscopic signs of the main histological variants of renal cell carcinoma. The ultrastructural profiles of rare forms of renal cell carcinoma included in the latest International Histological Classification of Kidney Tumors (WHO, 2016) are considered.

[Molecular basis of intratumoral heterogeneity of urinary tract urothelial carcinoma].

In the article the main mechanisms of molecular pathogenesis of urinary tract urothelial carcinoma are presented. Two different molecular pathways that determine the development of non-invasive and invasive urothelial carcinoma, the immunohistochemical spectrum of stem markers and aspects of the carcinogenesis of multifocal and recurrent tumors are considered.