Horseshoe kidney is the most typical kidney fusion anomaly among children (0.25%) and associated with various urological and non-urological abnormalities. Wilms' tumor is the most common malignant neoplasm of kidneys and the third most common solid malignant neoplasm in pediatrics. Wilms' tumor in a horseshoe kidney is rare (0.4-0.9%). The authors present Wilms' tumor in a horseshoe kidney and describe diagnostic methods, neoadjuvant chemotherapy and tumor resection.

To evaluate diagnostic features of large ampullary adenomas of the duodenum using endosonography, as well as to assess advantages of precise approach to resection of complex adenomas with intraductal component.

To determine the predictors of perforation following colorectal stenting for malignant stricture.

The aim of the study - to study the immediate and long-term results of surgical interventions for colon cancer with spread to the organs of the pancreatic duodenal zone.

To evaluate long-term postoperative outcomes in patients with hilar cholangiocarcinoma.

Neurofibromatosis type 1 is a hereditary disease with a wide variability of clinical manifestations, from the almost complete absence of typical symptoms to a multisystem lesion of the body. One of the possible clinical manifestations of this pathology is a pheochromocytoma - a tumor of the adrenal gland with the possible development of considerable cardiovascular complications. The article describes four cases of patients with pheochromocytoma as part of familial neurofibromatosis type 1, differing in clinical course from asymptomatic form to vivid paroxysmal manifestations. At the same time, the presence and degree of arterial hypertension did not correlate with the level of metanephrines and the size of the pheochromocytoma. 3 out of 4 patients have a hereditary history of neurofibromatosis type 1. In 1 out of 4 cases, simultaneous bilateral damage to the adrenal glands was noted, while the radiation characteristics of pheochromocytomas, both with computed tomography and CT/PET with 18-FDG, differed from the "classic" ones. An objective examination with the identification of "erased" signs of neurofibromatosis type 1 made it possible to establish the diagnosis of bilateral pheochromocytoma even with questionable laboratory and imaging data. Knowledge of clinical manifestations, timely diagnosis of neurofibromatosis type 1, comprehensive treatment and subsequent regular monitoring of patients, as well as examination of blood relatives can significantly improve prognosis and survival.

Pituitary adenomas (PA) are the most common lesions of hypothalamic-pituitary region. Clinical presentations of PA depend on both hormonal activity and tumor growth characteristics. Despite the fact that PA are mostly benign, they can grow invasively and mechanically affect adjacent structures. With invasive growth of PA, radical removal is difficult and associated with a higher risk of surgical complications. Pathogenesis of PA invasiveness is not fully understood. Tumor cell invasion depends on both intercellular interactions within the tumor and interaction with extracellular matrix components (ECM). Major factors that play an important role in these processes include matrix metalloproteinase (MMP) family and tissue inhibitors of matrix metalloproteinases (TIMPs). Two MMPs were mostly studied in PA - types 2 and 9. These molecules are of interest, as they participate in degradation of type IV collagen, which is a key component of the ECM in hypothalamic-pituitary region. This review discusses the general concept of PA invasiveness, the characteristics of MMPs, and research of the relationship between these molecules and PA invasiveness.

Ewing sarcoma is one of the two most common bone tumors in childhood and adolescence. More than half of cases occur in the second decade of life. Ewing sarcoma is rare in adults over 30 years old. Men prevail among patients (ratio approximately 1.5:1). Ewing sarcoma is rare in children of black and Asian races. Ewing sarcoma usually occurs in metaphysis or diaphysis of long bones of extremities. Lesions of pelvic bones, ribs and shoulder blades are less common. The most common foci of metastasis are lungs, bones and bone marrow. The authors describe a 12-year-old girl with Ewing sarcoma of pelvic bones. Chemotherapeutic treatment and surgical stage with simultaneous pubic bone repair with costal graft are described.

Colorectal cancer is one of the most prevalent oncological diseases, with rectal cancer accounting for a substantial proportion of cases. Surgical intervention remains the cornerstone of treatment, with its success significantly influenced by individual pelvic anatomy. Nevertheless, there is a notable scarcity of studies specifically focused on evaluating surgical complexity based on pelvic MRI pelvimetry.

To conduct a systematic review of literature data on robot-assisted multivisceral resections for locally advanced rectal cancer and to present own immediate results of these interventions.

Thyroid nodules in children are relatively rare; the risk of malignancy is considerably higher compared to adults. The optimal extent of surgery, the indications for radioactive iodine therapy (RAI), and the role of molecular genetic testing in children with thyroid carcinoma remain a matter of debate.

The basis of the vital activity of each cell of the body is energy metabolism, necessary for the implementation of physiological needs in norm and pathology. The most important pathways for the synthesis of adenosine triphosphate are glycolysis, the tricarboxylic acid cycle and oxidative phosphorylation. Glucose, free fatty acids and amino acids can be used as a substrate for obtaining energy. As the disease develops, reprogramming occurs in cells with the ability to switch between energy pathways and the choice of its sources, forming a specific metabolic phenotype that ensures cell survival and the formation of clinical characteristics of the disease. The availability of information on pathophysiological changes at the level of cell metabolism is of scientific and practical interest in relation to the development of methods for accurate diagnosis and the choice of personalized tactics in each specific case. This review describes the characteristics of energy metabolism in normal and tumor cells. It also provides information on modern methods for assessing energy metabolism in the body.

Neurofibromatosis type 1 (NF1) is a multisystem genetic disorder associated with a lifelong increased risk of tumor development. Comprehensive monitoring of patients with NF1, involving a multidisciplinary team of specialists and the implementation of screening programs, is crucial for the early detection of associated pathological conditions that contribute to disability and reduced life expectancy. This article presents a clinical case of an adolescent female patient with tumor manifestations of NF1, in whom both diagnosed neoplasms - plexiform neurofibroma and pheochromocytoma, had a symptomatic course, significantly affecting her physical health and quality of life. A multidisciplinary approach and correct treatment led to favorable outcomes, enabling the patient to resume a normal lifestyle, despite the continuation of targeted therapy.

The interest in neoadjuvant chemotherapy (NACT) for resectable ductal pancreatic cancer (PC) has increased significantly in recent years, primarily due to unsatisfactory long-term outcomes in these patients. However, oncological rationale for this approach is currently interpreted controversially. Routine NACT for resectable PC remains controversial due to the lack of uniform standards for regimens and number of drug therapy courses, selection criteria, high incidence of chemotherapy-related complications, toxicity, no evidence of benefit for all patients and risks of tumor transition to inoperable category due to delayed surgery. This review is devoted to effectiveness of NACT for resectable PC. The limitations of NACT and biological factors reducing its effectiveness are identified. NACT should not be considered as a standard for resectable PC without individual approach. The main tasks for future research should be criteria for selecting patients for NACT and standardized optimal regimens and number of chemotherapy courses.

To analyze the results of transanal endoscopic and robotic microsurgery for rectal neoplasms.

The authors describe a non-standard surgical approach to the treatment of tumor with predominant lesion of membranous tracheal wall. Circular resection with wide excision of membranous wall and replacement of tissue deficiency with autopericardial flap are used. This approach significantly reduced tension of anastomotic sutures, ensured smooth postoperative period and relapse-free survival over 7 years in context of combined treatment of adenoid cystic tracheal cancer.

The authors present surgical treatment of a patient with follicular thyroid tumor and parathyroid gland adenoma. Subsequent analysis recognized oncocytic thyroid gland adenoma manifested by clinical and laboratory picture of primary hyperparathyroidism. Multinodular goiter imitating parathyroid gland adenoma when one of the nodes is located behind thyroid lobe and intrathyroid location of parathyroid gland adenoma are factors complicating differential diagnosis. Therefore, this case of thyroid gland adenoma imitating functionally active parathyroid gland adenoma illustrates the need for alertness with respect to combination and mutual imitation of tumors of thyroid and parathyroid glands requiring surgical intervention. In addition, such cases require differential diagnosis between thyroid and parathyroid neoplasms based on all available laboratory and topical methods.

To demonstrate variable anatomy of inferior mesenteric vein and importance of preoperative vascular examination and imaging.

Colon cancer is one of the five most common cancers worldwide, leading to more than 500.000 deaths annually. It is known that the prevalence of colon cancer increases in parallel with increasing age, which is often associated with an increase in the number of concomitant diseases. The latter, both individually and in combination with each other, can have an impact on the safety of performing surgical interventions.

To determine prognostic factors in resectable common bile duct (CBD) cancer and feasibility of adjuvant therapy.