We present a case of a 24 -year-old woman, gravida 0, with menometrorrhagia and pelvic pain. A uterine hemorrhagic fibroid was diagnosed after ultrasound and magnetic resonance imaging (MRI). The endometrial biopsy was negative for mahgnancy. Laparoscopic sentinel lymph node sampling, lavage, and myometrial -biopsy with negative results were performed before dissection of the uterine vessels. The final diagnosis of endometrial stromal sarcoma was made by myomectomy and hysterectomy one year later. This case should demonstrate the difficulty of making the right diagnosis of sarcoma before laparoscopic dissection of uterine vessels in patients with symptomatic fibroids.