Spatial differences in biologic activity of large uterine leiomyomata

Objective To evaluate the growth pattern of the large uterine leiomyomata (ULM), we examined the spatial gene distributions, vessel density, proliferative activity, and hyaline degeneration. Design Tissue sections from three-dimensional large ULM, matched myometrium, and small ULM were collected and microarrayed. The spatial difference of the tumor activity was mapped in large ULM. Setting University clinical research laboratory. Patient(s) Hysterectomy specimens from 7 patients with large (>10 cm) ULM and 3 patients with large (>10 cm) uterine leiomyosarcomas. Intervention(s) Tissue microarray analysis by the immunohistochemistry. Main Outcome Measure(s) Selected gene products, vessel density, and the percentage of hyaline degeneration were all scored in tissue cores/sections of large and small ULM against matched myometrium. Result(s) We found that there was a spherical spatial difference of the tumor activities in large ULM. The tumor region next to the periphery, the most biologically active zone, demonstrated higher levels of gene expression, a higher density of vessels, a higher proliferative rate and a lower level of hyaline degeneration. The large ULM have higher levels of gene products (except for estrogen and progesterone receptors) than small ULM. Conclusion(s) In comparison of the spatial patterns of the gene activity between the large ULM and the large uterine leiomyosarcoma, the large ULM illustrate a growth pattern of nutritional dependence.