Newly formated (tertiary) lymphoid structures in tumor growth

Aim to reproduce tertiary lymphoid structures and study their features in a malignant neoplasm in the experiment. 
Material and methods. Male white rats of the Wistar stress-resistant line were inoculated with the tumor strain sarcoma M1. Using the methods of microsurgical preparation, color lymphography and ultrasonic sonolipodestruction we isolated the lymph nodes without metastatic lesions (described as secondary in normal anatomy), the lymph nodes with metastases of M1 sarcoma, and the newly formed nodes (extrauterine or tertiary). Lymph nodes were examined macroscopically, micromorphometric studies were performed, histological and immunohistochemical signs of tertiary lymph nodes were determined. The obtained data were subjected to statistical analysis. 
Results. In 60% of rats, in the right axillary region, in addition to the secondary lymph nodes described in normal anatomy, the tertiary lymph nodes were found on the side of the tumor. They were located near the histologically verified metastatic lymph node. The studied parameters of the main structural and functional zones of the tertiary lymph nodes had the following features: the enlarged marginal sinuses; a fewer number of lymphoid follicles; the average total area of blood vessels increased by 92% in relation to the metastatic lymph nodes and by 78% in relation to the secondary lymph nodes. The significant differences were registered with CD3, CD4, CD20, CD30 markers. 
Conclusion. The study proved the possibility of reproducing tertiary lymphoid nodes in the experiment with malignant growth and revealed a number of their features.