Ovarian cancer is the ninth most common malignancy and the fifth leading cause of cancer death in women in the USA. The majority of malignant tumors of the ovary are diagnosed at an advanced stage, making it the most fatal gynecological cancer. The aim of the current study was to determine whether there are differences in immunohistochemical tissue staining of cytokine tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) between benign tumors and malignant primary ovarian cancer. In total, 28 patients undergoing surgery for ovarian cysts were evaluated, and a diagnosis of benign neoplasm (n=14) or malignant neoplasm (n=14) was determined. An immunohistochemical study of histological sections of ovarian tumors was conducted. The results were analyzed using Fisher’s exact test, with P<0.05 indicating a statistically significant difference. Immunohistochemical staining of IL-10 was increased in malignant tumors compared with benign tumors (P=0.0128). For TNF-α, the immunohistochemical staining was more intense in malignant neoplasms, however, a statistically significant difference was not observed. These results indicate that the analysis of cytokines may be useful as a potential tissue marker of ovarian malignancy.