Immunohistochemical and electron microscopic findings in benign fibroepithelial vaginal polyps.

Eleven classic benign "fibroepithelial polyps" of the vagina were examined using a panel of immunocytochemical agents. Two were also examined electron microscopically. In all cases the stellate and multinucleate stromal cells characteristic of these lesions stained strongly for desmin, indicating muscle intermediate filament production. In common with uterine fibroleiomyomata, numerous mast cells were also often seen. Myoglobin staining was negative. Electron microscopical examination confirmed that the stromal cells contained abundant thin filaments with focal densities and also showed the ultrastructural features usually associated with myofibroblasts. It is concluded that these tumours would be better designated polypoid myofibroblastomas in view of the above findings.