[Transcriptome analysis of tissue microbiota diversity in tumor and non-tumor lymph nodes]. / Transkriptomnyi analiz raznoobraziya mikrobioty tkanei opukholevykh i neopukholevykh limfaticheskikh uzlov.

BACKGROUND: Metagenomic studies in recent years have demonstrated that all tissues of the human body studied by genomic and transcriptomic sequencing methods, both in pathological processes and in normality, contain fragments of DNA and RNA from a variety of microorganisms. The composition of tissue microbiota and its relationship with development of pathological changes are still poorly understood, despite increasing number of studies in this area every year. In this study, gene expression of the lymph node microbiome in reactive follicular hyperplasia and follicular lymphoma was investigated. OBJECTIVE: To study expression of lymph node microbiome genes in reactive follicular hyperplasia and follicular lymphoma. MATERIAL AND METHODS: The work included 38 biopsy samples of lymph nodes with follicular lymphoma of different cytological subtypes and 10 biopsy samples of lymph nodes with reactive follicular hyperplasia. Verification of diagnosis was carried out using standard histological, histochemical and immunohistochemical methods. Using sequencing method, the transcriptome was examined. Statistical analysis and data visualization were performed using the R programming language (version 4.2.1). RESULTS: Tumor lymph nodes are characterized by large Simpson and Shannon alpha diversity values (p-value = 0.026465 and p-value = 0.007122, respectively). Two clusters were discovered, characterized by different levels of relative abundance of microorganisms. CONCLUSION: It has been proven that diversity of microorganisms present in tumor tissue and their number are statistically significantly higher than corresponding indicators in the lymph nodes with follicular hyperplasia.

[WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues, 2022 (5th edition): Myeloid and Histiocytic Tumors]. / Klassifikatsiya VOZ opukholei gemopoeticheskoi i limfoidnoi tkanei 2022 g. (5-e izdanie): mieloidnye i gistiotsitarnye novoobrazovaniya.

The article reviews the changes in the structure of classification, diagnostic criteria for myeloid and histiocytic neoplasms in the 5th edition of the WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues (2022). Information is presented regarding new nosological forms, renaming and abolition of some previously existing ones. The importance of molecular genetic studies in the isolation of myeloid and histiocytic neoplasms and the need to apply these studies in clinical practice are emphasized. Myeloid and histiocytic precancerous and proliferative processes, genetic tumor syndromes, introduced into the classification for the first time, are considered.

[WHO classification of tumors of hematopoietic and lymphoid tissues, 2022 (5th edition): lymphoid tumors]. / Klassifikatsiya VOZ opukholei gemopoeticheskoi i limfoidnoi tkanei, 2022 g. (5-e izdanie): opukholi limfoidnoi tkani.

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.