2013 年 29 巻 2 号 p. 475-477
Isolated fallopian tube torsion is a rare disease; however, a paraovarian cyst may be a factor in inducing torsion. If an ovarian cyst exceeds 6 cm in diameter, the likelihood of adnexal torsion is high; thus, this situation is considered to be an indication for resection. A paraovarian cyst presents an equal likelihood of torsion; therefore, its presence also has a similar surgical indication. We experienced a case of a fallopian tube torsion that occurred with a paraovarian cyst of only 3 cm in diameter. When lower abdominal pain first occurred, this cyst was not considered to be its origin. We diagnosed the torsion three days after the onset of lower abdominal pain by preoperative computed tomography. At laparoscopy, the fimbria of the fallopian tube exhibited necrosis; therefore, we were forced to perform a salpingectomy. The literature contains reports of torsion of a normal fallopian tube and torsion of a hydrosalpinx; thus, it is necessary for gynecologists and emergency department physicians to recognize that tubal torsion can occur under these conditions as well as with a small paraovarian cyst.