Morphometric and Electron Microscopic Analyses of the Effect of Gonadotropin-Releasing Hormone Agonist Treatment on Arteriole Size in Uterine Leiomyomas

Abstract

Abstract Background.—Few studies have been performed on the vascular changes in leiomyomas from patients treated with gonadotropin-releasing hormone agonists (GnRHAs). Objective.—To measure luminal diameter and wall thickness of arterioles in uterine leiomyomas using a quantitative stereologic method of analysis. Design.—Thirty leiomyomas from 3 study groups were used: (1) patients treated with GnRHAs (10 patient samples), (2) age-matched controls (10 patient samples), and (3) postmenopausal women (10 patient samples). Measurements of arteriolar luminal diameter and wall thickness were made using a video-based, computerized system attached to the microscope, for which a morphometric ad hoc program was written. Electron micrographs were made of random arterioles from the first 2 groups (GnRHA-treated patients and age-matched controls). Setting.—Department of Pathology, Mount Sinai School of Medicine, New York, NY. Patients.—A total of 30 patient samples were studied, with 3 groups comprising 10 samples each, including patients treated with GnRHAs, age-matched control patients, and postmenopausal women. Results.—Arterioles in myomas from patients treated with GnRHAs had slightly larger luminal diameters and significantly thicker walls than age-matched controls and resembled arterioles from postmenopausal women. The thickening was due to smooth muscle cell hyperplasia in the muscularis media. Conclusions.—Treatment with GnRHAs causes a thickening of the walls of intramyomatous arterioles, which resemble those of postmenopausal women. This thickening may play a role in the decreased flow of blood reported in GnRHA treatment.