Intramural papilloma of the vagina: evidence of Müllerian histogenesis.

A papillary tumor occurred in the posterior-superior vaginal wall of a 5-year-old girl who was free of recurrence one year following surgical excision. The light microscopic features included papillae lined by eosinophilic cells with uniform, bland nuclei, solid areas of identical cells, and scattered glandular lumina which contained mucopolysaccharides. Foci of eosinophilic hyaline globules were another distinctive feature. Electron microscopy of the tumor demonstrated features associated with müllerian neoplasms including projecting microvilli, whorls of perinuclear cytoplasmic microfilaments, conspicuous lysosomes, squamous metaplasia, complex cytoplasmic interdigitations, and pseudoinclusions of "cytoplasmic" collagen. Previously described "mesonephric papillomas" of the vagina and cervix are compared with the tumor of the authors' patient. The previously described tumors share some histologic and clinical features, although they were superficial rather than intramural proliferations. The authors conclude that the ultrastructure, location, and documented presence of müllerian structures in the vagina favor a müllerian origin for this vaginal tumor. A number of other vaginal tumors that occur in children and young women show different light microscopic features.