Keywords : myxoid leiomyosarcoma ● uterine sarcoma ● mitotic index
Leiomyosarcoma of the uterus is a rare mesenchymal tumor with an incidence of 0.3 to 0.67 per 1,00,000 women1 and a poor prognosis. It must be distinguished from a uterine myoma with myxomatous changes.
A 31 year old P L was admitted from the outpatient clinic on 1st November, 2005 for a mass per abdomen and pain in the abdomen for the previous 1 month. There was no history of bladder and bowel complaints. Pain in the abdomen was un related to food habits. Her menstrual cycles were regular.
General physical examination was unremarkable. On abdominal examination there was a firm, nontender 18 weeks size mass palpable.
On bimanual examination a normal sized anteverted uterus deviated to the right side was palpated. A separate mass of about 16x12 cm was felt in the left fornix.
Sonography of the abdomen and pelvis showed a mass of 16.2x12.7x16.8 cms in the left uterine body. Right ovary was normal but the left ovary was not visualized.
With the diagnosis of a fibroid uterus laparotomy was performed under general anesthesia on 9th November 2006. It revealed a cystic, soft 15x10 cm left broad ligament fibroid. The uterus was deviated to the right side of the pelvis. Postoperative period was uneventful.
Histopathology of the specimen showed myxoid leiomyosarcoma of the broad ligament fibroid. After discussing the case with the oncologist, Wertheim’s hysterectomy was performed on 11th March, 2007.
Postoperative period was uneventful. Histopathology reported that the lymph nodes were negative for tumor, there was left tubal endometriosis, and the myxoid leiomyosarcoma extended into the surgically resected margins of the left parametrium.
The patient received 50 cg of external radiotherapy. She came for regular follow ups, with no symptoms and signs of recurrence of the tumor.
Uterine myxoid leiomyosarcoma is a rare mesenchymal tumor with an incidence of 3.9% 2. First described in 1982 3, it is characterized by a gelatinous appearance due to copious amounts of myxomatous stroma. The presence of myxomatous stroma is an indicator of a poor prognosis even in the face of low mitotic activity 4. The patients’ age ranged from 30 to 68 years. They commonly present with abnormal bleeding or pelvic mass. Distant metastasis to lung, liver and brain were found 2. The diagnostic criterion of leiomyosarcoma of more than five mitosis in ten high power fields cannot be applied in our case in whom mitosis were less than five high power field. King et al3 stated that a low mitotic rate and abundance of intracellular myxomatous tissue suggested that myxoid leiomyosarcoma might not be responsive to chemotherapy or radiotherapy. But the best treatment for this tumor is not known because there are too few cases to draw conclusions. A better prognosis is associated with premenopausal status, circumscribed margins, and low mitotic counts1. The myxoid variant may be an exception. It has a poor prognosis over all but perhaps has a more indolent course.
