[Two cases of supposed metastasizing leiomyosarcoma of the uterus].

Case 1. A 57-year-old female had hysterectomy 10 years ago because of leiomyoma uteri. She was recently found to have a clear-cut round mass shadow in the right middle lung field on her chest X-ray film 3. The mass was resected and microscopically diagnosed as metastatic leiomyosarcoma. Re-examination of the pathological specimen of the uterine tumor resected 10 years ago revealed 5-9 mitosis per 10 high-powered fields (/10 HPF). Case 2. A 54-year-old female who had undergone hysterectomy for myoma uteri 9 years previously was found to have a well-defined oval shadow in the left lower lung field which was resected and pathologically diagnosed as metastatic leiomyosarcoma. Her uterus lesion microscopically revealed 1-2 mitosis/10 HPF. The relationship between metastatic leiomyosarcoma of the lung and mitotic activity of leiomyoma uteri was discussed.