Malignant tumors of the salivary glands account for 3–5 % of all head and neck cancers. Adenocystic carcinomas are malignant neoplasms that most often arise from large and small salivary glands. The disease is characterized by a progressive course with local and distant relapses.
The article presents a clinical case of successful treatment with lenvatinib in suboptimal doses of adenocystic carcinoma of the parotid salivary gland.

Introduction. Head and neck tumors comprise about 7 % of all malignant neoplasms. In the head and neck area, tumors are usually located on the tongue (25–40 %) and floor of mouth (15–20 %). In the majority of cases, diagnosis, especially at early disease stages, is based on clinical and histopathological evaluation of tumor process. However, recently development and implementation of non-invasive techniques of early diagnosis of upper respiratory tract tumors through detection of pathognomonic volatile tumor markers in the exhaled air has become topical.
Aim. To evaluate diagnostic accuracy of sensory gas analysis device and artificial neural network for examination of exhaled gas samples from patients with oropharyngeal, laryngeal, laryngopharyngeal cancer and to establish the optimal conditions for sampling.
Materials and methods. The study included 28 patients with oropharyngeal, laryngeal, laryngopharyngeal cancers and 25 healthy volunteers. The proposed technique is based on analysis of samples of exhaled gas from the studied individuals using a diagnostic device developed by the authors. The device detects volatile compounds in the exhaled air using a set of semiconductor sensors with subsequent analysis by a neural network. The exhaled air was sampled using two methods: in the morning in the fasted state before daily hygienic procedures and physical activity (prepared samples) and in the context of everyday life, nutrition and hygiene without restrictions before sampling (non-prepared samples).
Results. Based on the signals from the sensors, the neural network classified and detected patients with malignant tumors. Accuracy of the prepared samples from healthy volunteers and patients with oropharyngeal, laryngeal, laryngopharyngeal cancers was 79.17 %, of non-prepared – 84.09 %.
Conclusion. High diagnostic accuracy of the developed technique of non-invasive diagnosis of malignant tumors of the oropharyngeal, laryngeal, laryngopharyngeal areas using exhaled air samples which does not require special preparation of the studied samples was demonstrated.

Aim. To optimize the choice of surgical approach based on the assessment of immediate and long-term results of microsurgical treatment of cerebellar meningiomas.
Materials and methods. Between 2019 and 2023 at the Department of Neurosurgery of the m.f. vladimirsky moscow Regional Research Clinical Institute, 24 patients with primary meningiomas of the cerebellum underwent microsurgical treatment. The ratio between women and men was 5:1, mean patient age was 51.5 years. mean tumor volume was 8.7 cm3. Neurological and neuroimaging data, information about concomitant disorders, surgical protocols, information on postoperative complications, functional outcomes, and catamneses of the patients were compiled.
Results. Total tumor resection was achieved in 22 (91.7 %) cases, subtotal in 2 (8.3 %) cases with grade I–II radicality per the Simpson classification. Deterioration and neurologic deficit were observed in 5 (20.8 %) patients. In 2 (8.3 %) patients, dysfunction of the abducens nerve was observed, in 3 (12.5 %) – impaired hearing or deafness, in 5 (20.8 %) – ataxia aggravation. postoperative complications developed in 2 (8.3 %) patients. No deaths were registered. grade 1 meningiomas were found in 22 (91.7 %) patients, grade 2 – in 2 (8.3 %) patients.
Conclusion. During microsurgical removal of tentorial meningiomas, optimal surgical approach takes into account the topographic and anatomical location of the tumor. This makes it possible to achieve safe and effective treatment with favorable functional outcomes.

Introduction. Transnasal endoscopic resection of sinonasal tumors is currently used in many clinics around the world. Short- and long-term oncological outcomes primarily depend on tumor histology. However, most currently existing studies are based on a small number of observations due to the rarity and heterogeneity of sinonasal malignancy.
Aim. To evaluate short- and medium-term oncological outcomes of treatment of malignant sinonasal tumors. Materials and methods. The study is based on retrospective analysis of 95 patients who underwent endoscopic surgery for sinonasal malignancy between 2014 and 2023 at the N.N. Blokhin National medical Research Center of Oncology. Squamous cell carcinoma was diagnosed in 27 (28.4 %) patients, olfactory neuroblastoma in 13 (13.7 %), mucosal melanoma in 30 (31.6 %), adenocarcinoma in (6.3 %), adenoid cystic carcinoma in 7 (7.3 %), sarcomas in 12 (12.7 %). Results. In the study group, 2-years overall survival and recurrence-free survival were 81.3 and 61.4 % respectively, survival without local recurrence was 87.5 %. The outcomes significantly depended on tumor histology.
Conclusion. Oncological outcomes of endoscopic resections of sinonasal tumors significantly depend on tumor histology, but in general they allow to achieve good local control. Small number of observations, variety of histological forms, and short follow-up periods do not allow to accurately evaluate the effectiveness of this approach for each tumor type. further research in large populations is needed to establish risk factors.

Introduction. metastases in the absence of a primary tumor (cancer of unknown primary (Cup) syndrome) are diagnosed in 2–4 % of malignant tumor cases. This pathology is characterized by early metastatic dissemination, weak response to conventional chemotherapy, and aggressive progression. The use of checkpoint inhibitors targeting programmed cell death protein 1 (pD-1) and its ligand (pD-L1) has shown good results in treatment of various cancers including oropharyngeal squamous cell carcinoma (OpSCC). In Cup syndrome, the effectiveness of checkpoint inhibitors is rarely investigated, and pD-L1 expression is often not measured.
Aim. To compare the frequency of p16 and pD-L1 hyperexpression in OpSCC and Cup syndrome, and to analyze dependency of survival rates on the level of expression of p16, the most important prognostic marker.
Materials and methods. The study included 121 patients (59 with OpSCC and 62 with Cup syndrome) who received medical treatment in the multidisciplinary medical Center “medical City” (Tyumen) and Chelyabinsk Oncological Center of Oncology and Nuclear medicine between 2019 and 2023. Immunohistochemical examination was performed using the vENTANA Benchmark gX with primary antibodies against pD-L1 (clone Sp263, uSA) and р16 (uS Biological, uSA). Statistical analysis of the data was performed using SpSS 26 software. Long-term treatment outcomes were evaluated using 1-, 3-, 5-year survival rates and median survival. Overall survival was analyzed using the kaplan-meier method. Statistical significance of the differences was evaluated using the Cox model.
Results. The studied groups did not differ by sex (p = 0.472), age (р = 0.640), and N stage (р = 0.262). patient age in the whole population varied between 42 and 81 years (median age 61.89 ± 11.9 years; mean age 60.81 ± 9.8 years). pD-L1 expression rate was higher in Cup syndrome at 92 % compared to 73 % in OpSCC (statistically significant difference; р = 0.01). Analysis of the association of ORSCC and Cup syndrome with human papilloma virus showed statistically significant difference in p16 hyperexpression: patients with OpSCC had p16-positive status more frequently (53 % of cases) while patients with Cup syndrome mostly had p16-negative status (73 % of cases). mean life expectancy of patients with OpSCC and p16-positive status was 62.65 months (95 % confidence interval 54.98–70.31), minimal observation period was 12 months, maximal was 70 months. mean life expectancy of patients with Cup syndrome and positive p16 status was 66.22 months (95 % confidence interval 56.35–76.10), minimal observation period was 12 months, maximal was 70 months. No statistically significant differences in survival rates of patients with OpSCC and Cup syndrome were found (р = 0.999).
Conclusion. The study showed higher pD-L1 expression in patients with Cup syndrome compared to patients with OpSCC: 92 and 73 %, respectively (р = 0.01). The obtained results highlight the importance of routine pD-L1 expression evaluation in patients with Cup syndrome. The frequency of p16 hyperexpression was higher in OpSCC compared to Cup syndrome: 53 % versus 27 % (р = 0.02) which agrees with the worldwide epidemiological data: among all malignant neoplasms of the head and neck, Hpv infection is most common in OpSCC. Therefore, it serves as an important sign of hidden oropharyngeal cancer in Cup syndrome.

Introduction. In the 10th revision of the International Classification of Diseases (ICD-10), the code for malignant neoplasms of pharynx (mNN) is C11. These tumors are rare. The state statistics only presents information on morbidity. Data on mortality due to mNN are absent, they are included into the group of other causes of death. The real assessment of the effectiveness of antitumor management of mNN can only be obtained from the population Cancer Registry Database (pCR DB) of the Northwestern federal District of the Russian federation (NwfD Rf) developed by us. This database allows to determine the main analytical values of any parameter included in the case report form. The most reliable criterion of evaluation of the effectiveness of antitumor management is calculation of observed and relative 1-year and corrected 5-year survival rates of patients at the population level and in accordance with international standards.
Aim. To perform first in Russia assessment of the effectiveness of antitumor management of mNN with calculation of analytical values including survival (separately for men and women) and detailed characteristics of location and histological structure.
Materials and methods. The data of the International Agency for Research on Cancer (IARC), as well as reference books of the p.A. Hertsen moscow Oncology Research Institute and the N.N. petrov National medical Research Center for Oncology were used. Data processing was preformed using mS Excel 2013–2016 and STATISTICA 6.1 licensed software. Survival rates were calculated using modified EuROCARE software. The study was based on the databases of the population cancer registry of Saint petersburg and NwfD Rf developed by us. In total, 950 observations were analyzed. Results. Data obtained during investigation of the incidence and survival rates of mNN confirmed the rarity of this pathology and positive morbidity dynamics, standardized values of which decreased in Russia between 2010 and 2022 by 19.35 %, in NwfD Rf by 27.59 %. The coronavirus pandemic had a significant negative effect on the record keeping. Additionally, between 2010 and 2022 1-year survival of patients with mNN in NwfD Rf increased from 58.5 to 80.6 % (by 22.1 %); 5-year survival increased between 2000 and 2018 from 25.4 to 35.4 % (by 10 %).
Conclusion. Analysis of the incidence and survival of patients with malignant neoplasm of rare location can be performed only using a database of population cancer registry of a federal district in compliance with all international rules of its maintenance. unfortunately, currently this is possible only for NwfD Rf.

Resection of malignant neoplasms of the oral cavity causes esthetic, functional, and anatomical defects irrespective of the advancement of tumor process. The methods of oral cavity organ reconstruction include the use of distant flaps and microsurgical autotransplantation. microsurgical techniques have limits and are not always applicable in clinical practice.
The article presents the main techniques of oral cavity organ reconstruction alternative to microsurgical techniques. Detailed literature review on this topic is performed, advantages and disadvantages of the various methods of defect reconstruction are presented. In clinical practice, the use of distant flaps is an adequate alternative to microsurgical autotransplantation. This method can be successfully used in weakened patients with locally advanced squamous cell carcinoma of the oral mucosa.

One of the rare neuroendocrine vascular neoplasms is paraganglioma. This tumor is diagnosed in 0.5 % of all cases of head and neck tumors. The treatment of choice for paraganglioma is open surgical intervention. The number of complications after this surgery remains high. The rarity of paraganglioma dictates the necessity of personalized approach to each patient with this pathology.
The article presents a clinical case of successful treatment of malignant paraganglioma. After open surgical intervention, control of the long-term results is necessary to prevent development of malignant process and disease recurrence.

Introduction. Despite visual accessibility of the elements of tumor lesions in the oral mucosa, patients with this pathology rarely seek medical help. Regeneration of the mucosa is a long process taking varying time depending on the location of the lesions. Asymptomatic tumor process leads to its diagnosis at late stages.
Aim. To develop clinical and proteomic approach to diagnosis of malignancies of the oral mucosa at the stage of out-patient dentist appointment.
Clinical observations. Examples of extended clinical, dental and immunoenzymatic monitoring in patients with elements of tumor lesions of the oral mucosa with long-term course are presented.
Conclusion. The use of extended clinical, dental and immunoenzymatic analysis of oral fluid in patients with elements of tumor lesions of the oral mucosa allows to diagnose this pathology early.