Giant Ovarian Mucinous Tumor Managed by Transvaginal Drainage of Tumor Contents Followed by Laparoscopic Resection: A Case Report

Laparoscopic surgery is widely preferred for benign ovarian tumors because it is associated with less postoperative pain, fewer complications, and shorter recovery time compared with laparotomy. However, laparoscopic surgery for giant cystic ovarian tumors occupying the entire abdominal cavity poses substantial challenges, including difficult trocar insertion and the risk of intraperitoneal spillage, particularly when the cyst contains highly viscous mucinous material that is difficult to aspirate with standard suction devices. We report a case of a 72-year-old woman with a 37.7 × 32.0 × 15.5 cm multilocular ovarian tumor extending from the pouch of Douglas to the upper abdomen. Ultrasonography suggested highly viscous contents, and magnetic resonance imaging showed no findings of malignancy. Given that the tumor markedly bulged into the pouch of Douglas, a transvaginal approach was selected to achieve safe decompression prior to trocar placement. Through a posterior colpotomy, the cyst wall was exposed extraperitoneally, enabling controlled extracorporeal incision and drainage of 9,782 mL of highly viscous fluid facilitated by manual abdominal compression. Tumor decompression enabled safe trocar insertion, pneumoperitoneum establishment, and laparoscopic adhesiolysis of dense adhesions to the abdominal wall and omentum. The adnexa were subsequently ligated and removed transvaginally without macroscopically evident intraperitoneal spillage of the tumor contents. Histopathology examination confirmed mucinous cystadenoma arising in a mature cystic teratoma. The patient experienced an uneventful recovery and was discharged on postoperative day 3. This case highlights that transvaginal drainage via posterior colpotomy is an effective strategy for giant ovarian cystic tumors with highly viscous contents, particularly when the tumor protrudes into the pouch of Douglas. Tailoring the surgical approach to the tumor’s anatomical characteristics can facilitate safe, minimally invasive management even in cases traditionally managed by laparotomy.