Immunohistochemical evaluation of lymphocyte types infiltrate into the canine seminomas

Seminoma is frequently observed in human and canine testes especially in cryptorchids. Canine and human seminomas are typically associated with leukocytic infiltration.

We aimed to identify the type of lymphocytes that infiltrate to seminomas.

Tumor infiltrating lymphocytes were evaluated by immunohistological techniques in 5 dogs with diffuse seminoma. Routine pathological examination of these specimens showed diffuse seminoma with tumor infiltrating lymphocytes in all cases.

Lymphocytes in seminomas were predominantly T cytotoxic (CD3+, CD8+) cells. These cells were distributed diffusely, but patchy around the vessels. B-cells were also identified as some rare single cells diffusely scattered in the tumoral parenchyma.

The results of this study showed that the lymphocyte infiltrating cells are mainly T lymphocytes particularly CD8 cytotoxic type.