Borderline ovarian tumors complicating pregnancy: a case report

Although the majority of ovarian tumors complicating pregnancy are benign, they still pose a challenge because of the difficulty in differentiating between benign and malignant tumors during pregnancy. To our knowledge, the value of color Doppler ultrasound in the diagnosis of borderline malignant tumors complicating pregnancy remains unclear. We present the case of a 29-year-old pregnant woman with an ovarian tumor of low malignant potential. Preoperative ultrasound revealed a well-encapsulated cystic complex on the left ovary measuring 16 x 18 x 12 cm with an internally smooth surface, multiple septa ranging from 2 to 4 mm in thickness and a small solid component 2 cm in diameter, with a resistance index of 0.42. The differential diagnosis preoperatively was a borderline tumor. The patient underwent a left oophorectomy at 18 weeks of gestation. Frozen pathology indicated a mucinous cystadenocarcinoma of low malignant potential. A thorough surgical staging was completed. The final pathology confirmed mucinous cystadenocarcinoma of low malignant potential, stage IA. Postoperatively, the patient had an uneventful course and did not receive any adjuvant therapy. She delivered a normal male fetus weighing 3,450 g at 38 weeks of gestation. We conclude that color Doppler ultrasound is helpful for the preoperative diagnosis of borderline tumors of the ovaries but its usefulness for making an accurate diagnosis may require further evaluation.