Morphometric and electron microscopic analyses of the effect of gonadotropin-releasing hormone agonist treatment on arteriole size in uterine leiomyomas

Background.-Few studies have been performed on the vascular changes in leio myomas 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 treat ed with GnRHAs (10 patient samples), (2) age-matched controls (10 patient s amples), and (3) postmenopausal women (10 patient samples). Measurements of arteriolar luminal diameter and wall thickness were made using a video-bas ed, computerized system attached to the microscope, for which a morphometri c ad hoc program was written. Electron micrographs were made of random arte rioles from the first 2 groups (GnRHA-treated patients and age-matched cont rols). Setting.-Department of pathology, Mount Sinai School of Medicine, New York, NY. Patients.-A total of 30 patient samples were studied, with 3 groups compris ing 10 samples each, including patients treated with GnRHAs, age-matched co ntrol patients, and postmenopausal women. Results.-Arterioles in myomas from patients treated with GnRHAs had slightl y larger luminal diameters and significantly thicker walls than age-matched controls and resembled arterioles from postmenopausal women. The thickenin g was due to smooth muscle cell hyperplasia in the muscularis media. Conclsuions.-Treatment with GnRHAs causes a thickening of the walls of intr amyomatous arterioles, which resemble those of postmenopausal women. This t hickening may play a role in the decreased flow of blood reported in GnRHA treatment.