Bone Formation in a Mucinous Cystadenoma of the Ovary - Report of a Rare Case.

Bone formation in the ovary is exceedingly rare, except in the setting of dermoid cysts. Here, the author reports a case of incidental finding of heterotopic bone formation in a mucinous cystadenoma of the ovary in a 45-year-old woman who had underwent a total abdominal hysterectomy and right salpingo-oopherectomy because of hypermenorrhea during last one year with an ultrasonography report of right ovarian cyst and simultaneous multiple uterine leiomyomatas. Microscopic examination of the ovarian cyst revealed a mucinous cystadenoma with the striking finding of several thin plates of lamellar bone identified in fibrous tissue in the cyst wall. Although it is a benign finding and does not seem to have prognostic significance, it may lead to sonographic findings of concern during the evaluation of ovarian cysts.