[Morphometric and histological evaluation of uterine leiomyomas treated with GnRH agonists or progestational agents]

Both gonadotropin-releasing hormone (GnRH agonists) and progestational agents are commonly used in order to reduce the size of uterine leiomyomas before surgery. So far, little is known about the histologic changes underlying such shrinkage mechanism. Probably the conflicting data on this subject are due to the qualitative and subjective methods used by most previous reports. In this study we analyzed 42 leiomyomas from patients treated with GnRH agonists (14 different patient samples), patients treated with progestational agents (14 different patient samples) and age-matched control patients (14 different patient samples), using qualitative (light microscope analysis) and quantitative (morphometric analysis by a specific software) methods. We assessed the following parameters: areas of necrosis, areas of hyalinization, vasal density, vasal thrombi, thickness of vasal walls, size of vasal lumina, cell density, maximum nuclear diameter, maximum cytoplasmic diameter, mitotic index on each sample. The analysis showed that leiomyomas from women treated with GnRH agonist exhibited broader areas of necrosis, greater cell density, and wider vasal lumina, while those from women treated with progestational agents exhibited thicker vasal walls than the other two groups, respectively. In conclusion, our results suggest that vasal wall changes are the basis of leiomyomas shrinkage after GnRH agonist therapy.