Teaching Case

A nulliparous 38-year-old patient with history of uterine fibroid suffered from urinary retention admitted to department of gynaecology. On physical examination, the clinician found a big pelvic palpaple mass.

MRI findings revealed that on the T2-weighted image (Fig. 1), there was an intramural uterine fibroid located on the anterior wall of anteflexed uterus with diameter of 150 mm considered as a type II (the signal intensity of uterine fibroid was higher than that of skeletal muscle and lower than that of myometrium) [1]. On perfusion-weighted image, uterine fibroid was regarded as a type A (the time signal intensity curve of uterine fibroid was lower than that of myometrium) (Fig. 2) [2]. The patient needed to undergo high-intensity focused ultrasound surgery instead of open surgery.

Uterine fibroid with prevalence of 70-80%, also known as leiomyoma, is one of the most common gynaecological benign tumours that impact negatively on the health of reproductive-age women. High-intensity focused ultrasound was performed based on the biological thermal effect of high intensity focused ultrasound on the convergent tissue to elevate the tissue temperature up to the threshold of coagulative necrosis and protein denaturation. In this case report, we displayed a case of huge uterine fibroid ablated in single phase high-intensity focused ultrasound successfully without any complications. Volumetric high-intensity focused ultrasound surgery under the guidance of magnetic resonance imaging ablation was exploited (Fig. 3), using 50 treatment cells (12 mm, n = 8; 14mm, n = 22; 16 mm, n = 20) and a mean power of 148 W. Placing one-layer cells on the same plane strategy was considered as a main treatment approach (Fig. 4). Posttreatment non-perfused volume ratio of 100% was achieved after 220-minute treatment duration (Fig. 5). At 12-hour post ablation, the patient was discharged without complications. At 6-month follow-up, the complaint symptom was resolved completely. Furthermore, serum anti-mullerian concentration of this case before ablation and after 6 months of treatment was preserved completely [3, 4]. We took advantage of the thermal accumulation in the near field to enhance the treatment efficacy by using a one-layer strategy. These results were in full agreement with some previous studies [5-7]; therefore, high-intensity focused ultrasound treatment should be considered as an alternative therapeutic method for patients with huge uterine fibroid.