A 53-year-old woman with a pelvic mass discovered by routing physical examination. a On ultrasound examination, a 28 mm*22 mm*26 mm well-circumscribed hypoechoic mass was observed in the right ovary, with posterior echo attenuation. b On laparoscopy surgery, right ovarian was hard and enlarged, the surface smooth, having a good mobility; in the pelvic, a small number of pale yellow ascites were observed. c Pathologically, right ovarian was enlarged, with tough textures and grayish white surfaces. d Pathological findings confirmed thecofibroma in right ovarian