Vol 3, No 1-2 (2020)

Epithelial tumors of the thymus are considered rare, but they make up the majority of tumors of the anterior mediastinum. The cytological diagnosis of thymic epithelial tumors, cytomorphological features of thymomas type A, AB, B1, B2, B3, some types of carcinomas and neuroendocrine tumors of the thymus are considered in the article.

Background. The development of hereditary cancer syndromes is associated with genetic defects in the DNA repair system, which includes more than 100 genes. In the majority of medical centers in Russia, the diagnosis of hereditary ovarian and breast cancer is based on the detection of the most common BRCA1 and BRCA2 gene mutation (8 loci) using polymerase chain reaction. However, these mutations are common for the Slavic population, while in other ethnic groups, they can be less frequent. Objective: to perform population analysis of mutations in the BRCA1 and BRCA2 genes. Materials and methods. We used next generation sequencing (NGS) to analyze BRCA1 and BRCA2 gene mutations in 1,094 patients with hereditary ovarian and breast cancers. Results. Using NGS, we identified 87 pathogenic mutations in the BRCA1/BRCA2 genes in 230 patients; there was a significant difference in the frequency of mutations between different ethnic groups studied (Slavs, Tatars, Bashkirs, and Chuvash). We have developed a public database of BRCA1/BRCA2 gene mutations and polymorphisms and their prevalence in different ethnic groups; this database is available at https://oncobrca.ru. Conclusions. NGS allows the detection of rare mutations typical of different ethnic groups, which is crucial for choosing an optimal chemotherapy regimen and developing screening methods, aimed at the identification of BRCA1/BRCA2 mutation carriers in the population.

Ductal carcinoma in situ (DCIS), also known as non-invasive breast cancer, accounts for approximately 20-25 % of all new breast cancer cases worldwide, while in the Russian Federation, this proportion does not exceed 1 %. DCIS is a heterogeneous group of tumors with various clinical manifestations, morphological features, and prognosis. The article covers morphological characteristics of different DCIS variants and criteria for assessing their nuclear grades.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare lung disorder characterized by focal neuroendocrine cell hyperplasia that develops de novo and results in peribronchiolar fibrosis and obstructive pulmonary disease. Differential diagnosis for DIPNECH should include neuroendocrine cell hyperplasia of other origin, which has a different clinical significance. Therefore, the diagnosis of DIPNECH should be based on clinical, radiological, and histological findings. This article describes several cases of pulmonary neuroendocrine cell hyperplasia of various origin and compares them.