Ovary: Miscellaneous Neoplasms

Abstract

Tumours can develop from any of the non-specialized ovarian mesenchymal tissues: these may be malignant, and it is not always possible to distinguish such neoplasms from a one-sided development of a mixed Müllerian tumour. The fibroma is the only common tumour in this group and is formed of small, thin, spindle-shaped cells with narrow ovoid nuclei running parallel to their long axis (Figure 30.1): these cells are arranged in interlocking bundles but the appearances may be markedly altered by oedema, hyalinization or myxoid change. Intracellular lipid is absent and this, together with the thinness of the cells, helps to distinguish a fibroma from a thecoma: it is admitted, however, that cases are encountered in which the histological features lie somewhere between those typical of a fibroma and those characteristic of a thecoma, and under such circumstances the rather unsatisfactory diagnosis of ‘fibrothecoma’ has to be made. Ascites complicate about 15% of ovarian fibromata and fluid may also accumulate in the pleural cavity to give a typical Meig’s syndrome: oedema of the legs, vulva and anterior abdominal wall is sometimes seen. Rarely, ovarian fibromata form part of the basal cell naevus or Gardner’s syndrome. Ovarian fibrosarcomata are very rare, the diagnosis depending upon the histological evidence of pleomorphism and mitotic activity, both features conspicuously absent from the benign fibroma.