Most studies state that it is necessary to surgically treat bilateral dermoid cysts of the ovaries during pregnancy if they are more than 60 mm in diameter. Laparotomy is a common procedure for surgery (
3), while laparoscopy is also sometimes used (
3). The preferred time of surgery is the second trimester of gestation (
3) the current study patient was a case of bilateral multiple benign dermoid cysts and was treated surgically by laparotomy approach in the 21st week of gestation.
The surgical approach of the dermoid cysts is important and most of the ovarian surgeries can be performed by laparoscopy. Mini laparotomy is another alternative between laparoscopy and laparotomy. Shorter operation time, removal of the mass with lower risk of rupture and preserving more ovarian tissue are some advantages of this approach in comparison to laparoscopy (
7). In the selected cases of adnexal mass during pregnancy, close observation is an accepted alternative to surgery in patients with an adnexal mass (
8). The gold standard to detect an ovarian tumor during pregnancy is ultrasound (
4).
Laparotomy was performed for the present case because there were bilateral, multiple dermoid cysts and intact removal of all cysts and preserving healthy remnant ovarian tissue were very important. To prevent complications such as torsion and based on the insistence of the patient to do surgery, surgical approach was employed. The ovarian mass was diagnosed by trans abdominal ultrasound performed by two sonologists.
During pregnancy, tumor markers are not reliable to assess the risk of malignancy of ovarian masses (
4). Surgery is recommended in patients with symptoms of adnexal torsion at any gestation. Laparoscopy is possible during the first and second trimester to manage symptomatic presumed benign ovarian tumors. The risk of miscarriage following surgery for ovarian tumor during pregnancy is estimated 2.8% and the risk of torsion is increased during the postpartum period (
4). Complete removal of the cysts, reduction of the risk of recurrence, prevention of the risk of tumor dissemination and preservation of healthy ovarian tissue should considered during the surgery of benign ovarian tumors (
9).
In the current case, the serum tumor markers were in normal ranges and complications did not occur before or after surgery; the route of surgery was laparotomy. In this case, all cysts were completely removed, all removed cysts were kept intact during surgery and the preservation of healthy ovarian tissue was performed optimally too.
Auto amputation of ovary may rarely develop following torsion of dermoid cysts and it may be more commonly implanted on the greater omentum. During cesarean section of a 33-year-old pregnant female the absence of the right ovary implanted in the cul-de-sac following torsion of dermoid cyst was incidentally observed (
10). A very rare complication of ruptured dermoid cysts is granulomatous peritonitis. Granulomatous peritonitis happened in a 27-year-old primigravida female postoperatively following surgical removal of a ruptured dermoid cyst in the second trimester of pregnancy (
11); another rare but ominous complication of mature cystic teratomas is malignant transformation. A case of squamous cell carcinoma developed from a dermoid cyst during pregnancy is reported (
12).
Fortunately, none of these complications occurred in the current study patient and her pregnancy was uneventful.
In conclusion, it seems that intact removal of multiple ovarian benign dermoid cysts by laparotomy during the second trimester of pregnancy could prevent complications of cysts and adverse pregnancy outcome.