Morphometric and immunohistochemical study of regional lymph nodes in gastric cancer

Aim. To perform quantitative analysis and immunohistochemical phenotyping of regional lymph nodes structural and cellular elements in gastric cancer in the absence and the presence of metastases.

Methods. The regional lymph nodes obtained during surgery for gastric cancer from 48 patients (31 men and 17 women, mean age 60.9 years) were studied. Histological sections were stained with haematoxylin and eosin, van Gieson stain, azure-II-eosin, pyronin by Brashe. Then morphometric analysis of lymph nodes structural and cellular elements was performed. A set of monoclonal antibodies against CD45, CD3, CD4, CD8, CD10, CD20, CD30, BLA-36, immunoglobulin (Ig) λ- and κ-chains, CD56, myeloperoxidase, CD68, lysozyme, α1-antichymotrypsin, CD35, S100, Ki-67, CD31, collagen type IV, vimentin, desmin was used for immunohistochemical reactions. Comparative study was performed in the following groups: (1) control group; (2) lymph nodes without metastases; (3) lymph nodes with metastases of different size.

Results. Paracortical and follicular hyperplasia, sinus histiocytosis, microcirculatory disorders and fibroplastic processes were found in regional lymph nodes in gastric cancer development. Paracortical hyperplasia was characterized by following immunohistochemical phenotype: CD 45, CD 3, CD 4, CD 8, CD 10, CD 30, CD 56, S 100, CD 31, Ki-67. CD45, CD20, BLA-36, CD10, CD30, CD35, Ig λ- and κ-chains, Ki-67 were mainly expressed in follicular hyperplastic reaction. The sinus reaction was accompanied by total cellularity increase with a predominance of CD68(+), α1-antichymotrypsin(+) and lysozyme(+) cells. Expression of CD3, CD4, CD8, CD10, CD56, Ki-67 decreased amid the paracortical zone area reduce in metastases development. Sinuses were devastated and poor with cellular elements, often with lymphostasis or sclerosis signs. Imunohistochemically there was moderate reaction with monoclonal antibodies against α1-antichymotrypsin, low - against lysozyme, myeloperoxidase, and high - against vimentin. Wherein follicular hyperplasia with high levels of CD20(+) B-cells, BLA-36(+) activated lymphocytes and Ig(+) antibody producing plasma cells persisted. At the same time microcirculatory disorders and fibroplastic processes progressed.

Conclusion. Structural components area ratio, cellular composition and immunohistochemical phenotype change in the regional lymph nodes in gastric cancer development, with significant differences between intact and affected lymph nodes; paracortical zone and sinuses area reduction with T-, NK-cells and macrophage markers expression decrease amid the preservation of follicular hyperplasia with high level of activated B lymphocytes and antibody producing plasma cells can promote metastases engrafment in lymph nodes and further cancer generalization.