Long-term outcome of ultrasound-guided focused ultrasound ablation for gestational trophoblastic neoplasia in the cesarean scar: a case report

BACKGROUND: The treatment of gestational trophoblastic neoplasia (GTN) is one of the success stories in medical oncology. GTN in the cesarean scar is a rare entity, but most cases need to be treated with hysterectomy or localized uterine lesion resection because of chemoresistant lesions and/or massive bleeding. We present a patient with post-molar GTN in the cesarean scar who was non-invasively treated with ultrasound-guided high intensity focused ultrasound (HIFU) to preserve the uterus and fertility. CASE PRESENTATION: A 32-year-old woman was diagnosed with low-risk GTN (FIGO Stage I: 2 prognostic score) after partial hydatidiform mole. The 5th cycle of chemotherapy was interrupted because of persistent hepatic toxicity and impaired ovarian reserve function. However, the uterine lesion persisted (diameter of residual uterine lesion in the cesarean scar: 2.0 cm). Therefore, ultrasound-guided HIFU treatment was performed. A significant gray-scale change was observed during the HIFU treatment. Color Doppler ultrasonography and contrast-enhanced ultrasound (CEUS) was performed to evaluate the ablation effectiveness. Color Doppler ultrasonography showed disappearance of the signal of vascularity and CEUS showed no perfusion in the lesion located in the cesarean scar. The uterine lesion was obviously shrunken one month after HIFU treatment. Menstrual cycle resumed 48 days after HIFU. HIFU treatment decreased the number of chemotherapy cycles and there was complete disappearance of the GTN lesion at 4-month follow-up. The patient has shown no signs of recurrence as of 58-month follow-up. CONCLUSION: Ultrasound-guided HIFU may be a useful alternative to lesion resection for GTN in the cesarean scar in patients who show chemoresistance or are not suitable for chemotherapy. It has the potential to ablate the residual uterine lesion noninvasively to preserve the uterus and fertility, avoiding perioperative risks of lesion resection, especially acute bleeding.