Immunocytochemical characteristics of submucosal uterine myomas

Background/Aim. Myomas of the uterus, the most common benign tumors, have been studied for decades from the aspects of different basic and clinical disciplines. Despite this fact, their pathogenesis is still poorly understood. The aim of this study was to determine immunocytochemical characteristics of smooth muscle cells and connective tissue components of submucosal myomas of the uterus. Method. During the course of this study, 25 samples of submucosal myomas of the uterus were analyzed, all of them obtained during the surgery, after abdominal histerctomy by Aldridge. The samples were fixed in 4% formalin and embedded in paraffin. Sections of 5 mu m thickness were stained immunocytochemically using the DAKO LSAB+/HRP technique to identify smooth muscle muscle actin (alpha-SMA), vimentin, desmin, CD34, CD45, CD68 and PCNA (DAKO specification). Results. Our results suggest that submucosal myomas of the uterus are build-up of smooth muscle cells which are immunoreactive to alpha-SMA and desmin, but also to a certain number of smooth muscle cells which are immunoreactive to alpha-SMA and vimentin. Some of vimentin-immunoreactive cells also show an immunoreactivity of PCNA. In the build-up of connective stroma CD34-immunoreactive fibroblasts and neovascular formations are also present. By examining the distribution of CD45 antigen, at all the analyzed samples we observed a weak reaction. Conclusion. Submucosal myomas of the uterus are made-up of smooth muscle cells of the highly differentiated contractile phenotype (alpha-SMA- and desmin-immunoreactivity), as well as smooth muscle cell of the synthetic phenotype which proliferate (alpha-SMA-, vimentin- and PCNA-immunoreactivity). In submucosal myoma of the uterus there is a significant presence of connective tissue as a result of synthetic activity of fibroblasts, which clearly differ in their immunocytochemical characteristics from smooth muscle cells of the synthetic phenotype.