Myxoid leiomyosarcoma of the uterus

A case of myxoid leiomyosarcoma of the uterus is presented. In contrast to 10 of the 11 previously published cases, our patient has a tumor with a high mitotic rate.

The patient presented with a 2-month history of vaginal bleeding and a 20-week-size uterine mass. A total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed. At the time of surgery, the tumor appeared well circumscribed. Microscopically, an infiltrative growth pattern, bizarre nuclei, and 30 abnormal mitotic figures per 10 high power fields were noted. The patient was treated with ifosfamide and mesna. After the fifth course of chemotherapy, a pelvic mass was palpated. Exploratory laparotomy demonstrated a large sidewall recurrence and upper abdominal metastases which were completely resected. The patient is currently being treated with combination chemotherapy consisting of vincristine, Adriamycin, and cyclophosphamide.

Ten of the 11 previously reported cases of myxoid leiomyosarcoma had a low mitotic count. However, our patient has a high mitotic count in combination with an infiltrative growth pattern. Ifosfamide was ineffective as adjuvant chemotherapy and there was aggressive tumor growth while the patient was on this regimen.