The effect of steroid hormones on the size of myometrial cells : a morphometric study

Abstract

The aims of this study were to measure: 1. Myometrial cells of menopausal uteri to establish whether they atrophy after the menopause. 2. Myometrial cells at different phases of the menstrual cycle to investigate the influences of oestrogen and progesterone during the cycle. 3. Myometrial cells in the fundus and lower uterine segment to establish whether they differ in size. 4. Myometrial cells of pregnant uteri to investigate the effect of the hormonal status of pregnant women on the size of myometrial cells. 5. Neoplastic cells of leiomyomas of the uterus to investigate whether these benign tumours behave in the same manner as myometrium or, because they are neoplastic, they react differently. A preliminary investigation was undertaken to establish the optimal methodology for this study to measure myometrial and leiomyoma nuclei in the uterus. The aims of this preliminary investigation were: 1. To test the reproducibility of measurements of myometrial and leiomyoma nuclei in transverse and cross section. 2. To test five histological staining methods to ascertain the best method for a morphometric study on uterine cells. 3. To find the minimum sample size of nuclei per section of myometrium or leiomyoma in order to yield statistically significant results. This preliminary study found that the Haematoxylin and Eosin stain gave the most statistically reproducible measurements. Subjective assessment of the five staining methods also found Haematoxylin and Eosin to be optimal. It was also found during the preliminary study that measuring the myometrial nuclei in cross rather than transverse section gave the most statistically reproducible measurements. It was also found that it was best to use an axial ratio criterion of 0,9 when measuring cross-sectioned myometrial nuclei. The optimum sample size per section was also investigated and it was found that measuring 100 nuclei was optimal. It was found that in the uteri used in this study there was no statistically significant decrease in nuclear size after the menopause. It was also found that there was no statistically significant difference in nuclear size during the different phases of the menstrual cycle. There was also no notable difference in nuclear size between nuclei in the fundus and lower segment of the uteri in this study. It was found that there was a significant increase in the size of nuclei in leiomyomas compared to the normal myometrial nuclei from the same patient. The myometrial nuclei from pregnant uteri were also significantly larger than those from non-gravid uteri.