Morphofunctional and immunohistochemical characteristics of different clinical-pathogenetic types of leyiomyoma

Abstract

Introduction. Now the uterine leiomyoma (LM) remains the most common benign tumor of the female genitalia. Data on the histological composition, structure and properties of expression of hormones receptors of LM tissue are important for understanding the mechanisms of development of various clinical and pathogenetic variants of the tumor.

Aim is to study the relationship between morphological and immunohistochemical features of LM with a pathogenetic variant of the disease development aimed at developing differentiated methods of tumor treatment.

Materials and methods. The research included 188 women of reproductive age (30 to 49 years old) who underwent hysterectomy for symptomatic LM. Depending on the presence of concomitant pathology of mammary gland (MG) and thyroid gland (TG), patients were divided into groups: the first group were 67 (35.64 %) women with isolated LM (ILM), the second – 32 (17.02 %) patients with a combination of LM and dyshormonal diseases of the MG (DSMG), the third – 48 (25,53 %) women with LM associated with thyroid pathology, and the fourth – 41 (21.81 %) patients with a combination of LM, DSMG and thyroid pathology – combined leiomyoma of the uterus (CLU). The morphofunctional condition of the removed tissue and the proliferative potential of LM were determined by the results of histological, ultrastructural, immunohistochemical studies (antigen of receptors for estradiol, progesterone, prolactin, type IV collagen, nuclei of proliferating cells and chancer-embryonic antigen) by indirect streptavidin-peroxidase method using Kit-monoclonal antibodies.

Results. Single tumors occurred in 28.13 % of cases in patients of II, in 39.58 % – III and in 17.07 % – IV groups, which was significantly less than in women of group I (74.63 %; p < 0.05). In the morphological structure of uterine fibroids, removed from women of the I group, fibrous tissue prevailed in 80.6 % of cases, whereas in 73 % of the combined tumors smooth muscle components were found. According to the results of immunohistochemical studies, the highest positive expression rate of type IV collagen antigen (60.0 %) was observed in patients of group I against the background of low sensitivity to estrogens (H-score 25.83 ± 7.12), high – to progesterone (H-score 108.54 ± 12.66) and medium to prolactin. In combined leiomyoma, the highest level of receptor antigens expression to sex steroid hormones (estradiol and progesterone), prolactin (78.57 %) and markers of true proliferation and malignancy: PCNA (64.29 %) and CEA (42.86 %) was noted. For example, 84.0 % of patients in Group IV have an average expression of estrogen receptors, 76.0 % have a high level of progesterone expression in the nuclei and cytoplasm of myocytes with a high average expression in the H-score of the progesterone receptor antigen (209.94 ± 16.34), which is significantly higher than in women in group I (108.54 ± 12.66, p < 0.05). The findings indicate large hormone dependence, proliferative potential and the likelihood of malignancy of the combined uterine leyomyoma.

Conclusions. Isolated uterine leiomyoma is mostly represented by large single, nodular formations that have a low sensitivity to sex steroid hormones with a superiority of progesterone, and a negligible risk of malignancy. The uterine leiomyoma, in combination with the thyroid and mammary pathology, is characterized by multiple diffuse, small nodular tumor formation with pronounced expression to sex steroid hormones, including estradiol, accompanied by high growth potentials and a significant probability of malignancy.