Morphological Features and Histogenesis of Canine Nodal Lymphoma

Abstract

Introduction. One of the most common types of oncopathologies are lymphoproliferative disorders, in particular, lymphomas. The disorders are characterised by the complicated development mechanisms, multiple etiological factors and their diverse biological features. In addition, the common origin of lymphoid cells makes different types of lymphomas morphologically similar and complicates their diagnostics. The morphological study used to be, currently is and will continue to be a gold standard in the oncological pathology diagnostics. However, the lack of clear morphological criteria and histological classifications of the various types of tumours in animals prevents from adequate diagnostics of oncological diseases in them. The above urges to conduct a thorough study of various morphological types of lymphomas to identify their differential diagnostic features. The aim of the research is to study the morphological features and histogenesis of canine nodal lymphoma to facilitate the diagnostics and develop the efficient targeted therapy protocols.Materials and Methods. The objects of the study conducted in the network of veterinary laboratories “VETLAB” (Moscow) in the period from January 2024 to January 2025 were the lymph nodes in dogs with the signs of nodal lymphoma. All samples (n = 30) were prepared according to the standard technique of histological sample preparation. Histological preparations stained with hematoxylin and eosin were obtained, and microscopy was performed. A comparative estimation and contrasting against the following morphological criteria were carried out: tumour growth pattern, spread of tumour in the tissue, tumour cell structure, size and location of nuclei, chromatin structure, presence of mitoses, and tumour microenvironment.Results. By studying the canine nodal lymphoma features by means of microscopy, a number of significant differential diagnostic features were identified enabling to distinguish the following morphological variants of lymphomas: large-cell and small-cell lymphomas, immunoblastic, centroblastic and lymphoblastic lymphomas. Prognostic features included: proliferative index, diffuse growth pattern, cellular microenvironment, and tumour vascularization.Discussion and Conclusion. The study had identified the main morphological variants and cell types of canine nodal lymphomas. Morphological features and differential diagnostic criteria for microscopic study of lymphomas were determined. The obtained data can be used in the every-day practices of a pathologist for morphological verification of canine lymphomas, and also become the basis for histological classification of tumours of lymphoid tissue in animals.