Failure of ulipristal acetate treatment as an indication for uterine malignancy: Two case reports

INTRODUCTION: To study the clinical, pathological and therapeutic implications of ulipristal acetate (UPA) treatment failure in patients affected by uterine smooth muscle tumors. CASE PRESENTATION: Two patients affected by uterine leiomyosarcoma were preoperatively diagnosed as uterine leiomyomas and, thus, treated conservatively with UPA and morcellation. Both patients experienced a worsening of symptoms (persistent bleeding) after 3 month of treatment with UPA. Therefore a myomectomy with morcellation of tumor specimens was performed. Pathological examination of morcellated specimens revealed the unsuspected diagnosis of leiomyosarcoma based on the presence of severe nuclear atypia, tumor necrosis and increased mitotic activity. Unfortunately after 6 month of follow-up, 1 patient died for multiple peritoneal recurrences and lung metastases. The other patient is still alive after 3 month of follow-up and shows no local recurrences or metastases. CONCLUSION: Our reported cases emphasize that the poor or absent response to UPA treatment in addition to the instrumental evidence of a single mass may be indicative of the presence of an unsuspected leiomyosarcoma clinically and radiologically misdiagnosed as leiomyoma. The awareness of this possibility would avoid a delay in the diagnosis as well as unuseful and potentially dangerous treatments such as morcellation.