Renal cell carcinoma (RCC) accounts for more than 90% of cases of malignant kidney tumors and represents 2-3% of all malignancies worldwide. Clear cell renal cell carcinoma (ccRCC), the most common type of RCC, comprising 70-80% of cases. RCC most commonly metastasizes to the lungs, bones, lymph nodes, liver, adrenal glands, and brain. Synchronous metastasis of RCC to the ipsilateral ureter represents an extremely rare event. Ureteral metastasis is a significant diagnostic challenge, since it is quite difficult to determine whether it has metastatic origin (RCC) or it is a primary urothelial tumor. Moreover, due to the rarity of disease, treatment strategy is not well established. We present a rare case of patient with the RCC of a single left kidney and metachronous metastasis to the ipsilateral ureter that was initially assumed to be primary urothelial carcinoma. The robotic-assisted left-side partial nephrectomy with a segmental resection of left lower ureter and Boari reconstruction was performed. This case of successful treatment with robotic-assisted approach shows a great organ-sparing potential of robotic surgery in the treatment of complex oncological patients for whom it is extremely important to preserve the maximum volume of functioning renal tissue, particularly in those with a metastatic RCC of a single kidney.

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.

To evaluate the possibilities of textural analysis of 3D models in differentiating the degree of nuclear dysplasia of the clear cell renal cell carcinoma (ccRCC).

Surgical removal of cranio-orbital meningiomas is an effective method of treating this pathology. Modern surgical techniques and technologies make it possible to perform operations with a low risk of complications. Lumbar drainage or repeated lumbar punctures are often used intraoperatively or in the early postoperative period to prevent nasal CSF leak; this rarely leads to the development of significant neurological symptoms. We present a case of the development of severe intracranial hypotension with the formation of a subdural hygroma in the early postoperative period after removal of a cranio-orbital meningioma in a 41-year-old patient. The operation was performed using an individual model and molds for simultaneous reconstruction of the bone defect with an implant made of polymethyl methacrylate. On the 1st and 2nd days after surgery, lumbar punctures were performed. From the 2nd day there was a progressive deterioration with the development of symptoms characteristic of intracranial hypotension. Computed tomography revealed an increasing displacement of the midline structures of the brain and an increasing volume of epidural fluid accumulation in the area of surgical intervention. Magnetic resonance imaging revealed characteristic signs of intracranial hypotension. Conservative treatment (bed rest, active hydration) had no effect. On the 6th day after surgery, an epidural blood patch procedure was performed and closed external drainage of the epidural hygroma was performed, and a rapid regression of neurological symptoms was noted. Our experience and literature data indicate that it is necessary to remember the possibility of developing clinically significant intracranial hypotension even after a single lumbar puncture. The formation of hygromas in the surgical area is characteristic of intracranial hypotension, but in most cases does not require additional surgical intervention and does not have a negative impact on the outcome of treatment. Conservative treatment of intracranial hypotension is the first choice and often sufficient. If there is no effect and the patient's condition worsens, it is necessary to perform an epidural blood patch procedure.

To investigate the impact of resection quality on subsequent survival of patients with glioblastoma.

Pathogenesis of peritumoral cerebral edema is unclear and potentially associated with glymphatic system dysfunction. Diffusion tensor MRI (DT-MRI) with analysis of ALPS (Analysis along the Perivascular Space) index may be valuable for assessment of edema. This approach visualizes fluid flow along perivascular spaces of deep cerebral veins.

One of the important problems in microsurgical resection of intramedullary spinal cord tumors is excessive surgical aggression and subsequent neurological impairment. Laser fluorescence spectroscopy with electrophysiological monitoring provides high-quality resection of intramedullary tumors with monitoring of spinal cord structures in real time. This approach increases safety and quality of resection.

Atypical fibroxanthoma (AFX) is a rare skin tumor characterized by a combination of a «malignant» morphological features and non-aggressive clinical course. Diagnosing AFX is challenging due to histological «diversity» and heterogeneous immunophenotype. The presented review describes the history and evolution of AFX as a nosological form of cancer, its histogenetic origin, pathogenesis and biological potential. The clinical, morphological, immunohistochemical, molecular cytogenetic characteristics and histological subtypes of the tumor as well as differential diagnosis have been presented in detail.

The group of undifferentiated round cell sarcomas, according to the World Health Organization Classification, in addition to Ewing's sarcoma (ES), includes round cell sarcoma with rearrangement of the EWSR1 gene with partners not from the ETS gene family, sarcoma with BCOR gene alterations, CIC -rearranged sarcoma. Despite the fact that all tumors have clear histological and immunological criteria, their diagnosis can be difficult, given the fact that there are overlapping variants of the morphological picture and immunophenotype both within the group and with other round cell tumors.

Tumors of the salivary glands account for no more than 5% of all neoplasms of the head and neck. About 70% of all benign neoplasms of the salivary glands are pleomorphic. One of the rare localizations of pleomorphic adenoma is the larynx. Not more than 30 cases of laryngeal localization of pleomorphic adenoma are described in the literature currently. The article presents the result of organ-preserving surgical treatment of the patient with large pleomorphic adenoma of the larynx.

Cancer-associated fibroblasts (CAFs) often form a major component of the tumor microenvironment (TMA), providing conditions for cancer cells to thrive. CAFs may contribute to tumor growth, invasion, metastasis, and resistance to therapy. However, clinical trials of treatment strategies targeting CAFs have largely failed. Moreover, there is evidence that CAFs are capable of inhibiting tumor development. The review considers the current data on the functional heterogeneity of CAFs and their bimodality in tumor development and progression. Understanding the tumor-promoting and tumor-inhibiting activities of CAFs can help to develop new diagnostic and therapeutic approaches.

To analyse safety and expediency of cardiac surgical technologies including cardiopulmonary bypass (CPB) in patients with locally advanced lung cancer and invasive tumors of the mediastinum.

This review is dedicated to E-cadherin, a calcium-dependent cell-cell adhesion molecule with pivotal roles in epithelial cell behavior, tissue formation, and carcinogenesis. We summarize the structure of the E-cadherin, its role in the development of the body and in the carcinogenesis. The structure of the E-cadherin/β-catenin/αE-catenin complex and its relationship with the actin cytoskeleton are described in detail. The role of E-cadherin in the development of some infectious diseases, the function of E-cadherin as both a tumor suppressor and a promoter of tumor dissemination, its influence on signal transduction pathways in cells are highlighted. Particular attention is paid to the expression of E-cadherin in Helicobacter pylori infection and in tumor tissue in gastric cancer.

The article describes a rare case of small cell neuroendocrine carcinoma of the endometrium in a 67-year-old woman. According to the literature, only about 90 such observations have been described worldwide. Histological examination revealed three necessary features: the small-cell nature of the tumor, the presence of epithelial and neuroendocrine markers. An IHC study revealed a positive expression of Syn, Chrom A, CD56, CK AE1/AE3 markers; the proliferative activity index was 70%.

Neuroblastoma (NB) is a malignant neoplasm originating from the primary cells of the sympathetic nervous system. Patients with NB are risk-stratified using a number of features including age at diagnosis, disease stage, tumor histology and genetic profile (status of NMYC, ALK genes, regions 1p and 11q). The interpretation of the results of genetic studies can become a source of problems because neuroblastoma has a heterogeneous histological pattern. The article describes 2 cases with classical for NB chromosomal aberrations in the stromal component of the tumor.

In 2022, the 5th edition of the of the WHO Classification of Tumours of Endocrine Organs was published, which outlines the current understanding of adrenocortical cancer (ACC), resulting from interdisciplinary research over the past decade. This article highlights the new provisions of the WHO classification for the morphological diagnosis of ACC.

The paper discusses changes in the structure of the classification, criteria for the diagnosis of lymphoid neoplasms in the 5th edition of the WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues (2022). Changes are presented regarding new nosological units, renaming and abolition of some previously existing ones. The importance of molecular genetic studies in the isolation of many lymphomas and the need to apply these studies in everyday clinical practice are emphasized. Lymphoid precancerous processes and lymphoid proliferations introduced into the Classification for the first time are considered.

Mutations in the PIK3CA gene, encoding the catalytic subunit of the PI3K class IA p110α, is a common mechanism of activating of PI3K/AKT/mTOR pathway in breast cancer (BC). The detection of these mutations in patients with hormone-positive Her2-negative BC is of important clinical value, since they are the predictor of the sensitivity of the tumor to the PI3K inhibitor - alpelisib. According to the status of the Her2/neu expression, all patients with hormone-positive Her2-negative BC can be divided into two groups - with low expression of Her2/neu (IHC 1+; 2+, ISH-) and with a complete lack of expression of this protein (IHC 0).

Schwannoma is a benign neoplasm that develops from the Schwann cells of the nerve sheath. The share of neurogenic tumors of the parapharyngeal space accounts for 0.5% of all neoplasms of this localization. The article demonstrates a case from practice, presents the clinical features, diagnostics and methods of treatment for patients with pharyngeal neuromas. The peculiarity of the presented clinical observation is due to the rare occurrence of this pathology and the large size of the schwannoma in the long-term asymptomatic course of the disease.

The diagnostic value of calcitonin measurement in fine-needle aspiration biopsy wash-out fluid is a promising tool in the diagnosis of medullary thyroid cancer.