A case of pure uterine lipoma: immunohistochemical and ultrastructural focus.

Background Pure uterine lipoma is a rare clinical event and only a few cases have been reported in literature. The histogenesis of these lesions is still debatable. Preoperative diagnosis is difficult and should be pathologically confirmed postoperatively. Case We report the case of a 58-year-old woman who presented with pelvic pain and postmenopausal uterine bleeding. The hysterectomy specimen showed a pure intramural lipoma of the uterus. An immunohistochemical study revealed that the lipomatous tissue was reactive to S-100, vimentin, actin and desmin. Electron microscopy examination revealed bundles of spindle cells with intracytoplasmatic vacuoles and parallel-arranged intermediate filaments in the surrounding zone, in which adipose cells were mixed with muscular cells. Discussion Clinical and histological diagnosis of pure uterine lipomas are described and a possible involvement of fatty metaplasia of smooth muscle cells in the development of pure uterine lipomas is discussed.