[Parovarian cysts].

Histologic material from 117 cases of parovarian cysts through 1979 to 1984 was reviewed. The majority of these lesions were paramesonephric (mullerian), mesonephric and mesothelial in origin. Most patients were without symptoms. On microscopic examination a basement membrane may be demonstrated beneath the mesonephric epithelium, although such a layer is usually absent in the mullerian structures. Eight specimens show stratification of the epithelial lining of the papillae, four of these are parovarian cysts of low grade malignancy. These neoplasms were associated with normal tubes and ovaries. Follow up data on four low grade malignant cases showed they were living and well.