Osseous metaplasia in leiomyoma: A first in a uterine leiomyoma.

Being one of the commonest tumors of the female genital tract during the reproductive years, the leiomyoma uteri expectedly demonstrates a wide spectrum of histological variations. However, heterologous tissue differentiation is a rare finding and frank bone formation is even rarer. The factors that lead to heterologous tissue formation in a leiomyoma are subject to speculation. This is a rare case report and possibly the first, on the formation of pure mature bone in a uterine leiomyoma.