Our small experience is in line with the growing evidence that most of the large ovarian tumors characterized by a predominantly cystic component have a high likelihood of benignity [2]. The most significant predictors for a presumptive benign diagnosis include negative serum tumor markers and the prevailing cystic appearance of the tumor at imaging [1]. Therefore, ovarian-sparing surgery should be encouraged as the preferred option to preserve function of the unaffected parenchyma while not compromising tumor control. Indeed, the major challenge when approaching these lesions resides in their large size that increases the risk of tumor rupture. Nonetheless, a preemptive in situ drainage of the cystic component of the tumor may allow exteriorizing the collapsed tumor outside the abdominal cavity with a relatively low risk of tumor spillage. To achieve this goal, we adopted the leak-proof technique that was originally designed for drainage of large ovarian cystic tumors in adults [4]. The technique entails gluing a sterile plastic film onto the exposed surface of the tumor to reduce the risk of intrabdominal spillage during drainage of the fluid content of the tumor. Notably, Ehrlich et al. first described the leak-proof technique for excision of large cystic ovarian tumors in the pediatric population [3]. However, all the nine treated patients underwent oophorectomy or salpigoophorectomy following controlled drainage of the cystic component of the tumor. Notably, histology disclosed a benign nature of all tumors except one immature teratoma with grade 2–3 immature elements not requiring further treatment. Ovarian-sparing surgery was instead taken increasingly into consideration in subsequent pediatric experiences adopting the same precautionary leak-proof technique [5,6,7,8]. In the two largest case series available to date, ovarian-sparing surgery was successfully performed in 5/17 (29%) [5] and 17/23 (74%) [6] of cases, respectively. The increasing adoption of ovarian-sparing surgery is well justified by the excellent oncologic outcomes documented in all but one of the published pediatric cases with large cystic ovarian tumors, regardless of the type of surgery received. The only dismal outcome was reported in a girl with a mucinous cyst adenocarcinoma with evidence of preoperative rupture and positive peritoneal cytology, who died despite receiving adjuvant chemotherapy [6].

We have refined the leak-proof technique by using a balloon trocar, which creates a tight seal and facilitates closed suction drainage, thereby reducing the risk of tumor cell spillage. Previous stratagems for decompressing large cystic ovarian tumors typically involved making a small surgical incision in the center of the glued area and utilizing a standard suction tube for drainage [4, 6]. Unfortunately, this approach can lead to some fluid spillage that accumulates in the protected space covered by the impermeable layer, making effective suctioning necessary for proper management.

Other means of decompression have included the use of a Veress needle [3], a 16-gauge intravenous cannula [5], or a 16-gauge epidural needle [8]. In the latter case, the epidural needle is inserted into the tumor, passing through a nasopharyngeal airway that is glued to the tumor surface to help prevent spillage. However, the use of small-caliber tubes for drainage can be problematic, as they are prone to blockage from the semisolid debris often present in cystic ovarian tumors. Another technique that has been advocated involves the SAND balloon catheter, which contains an inner needle designed to pierce the tumor wall [7]. This allows for the catheter to be advanced and securely positioned inside the tumor by inflating a distal balloon, thereby preventing leakage during drainage. The stability of the catheter is further enhanced when the proximal balloon is inflated, lying just outside the tumor wall. While this approach allows for a closed suction drainage similar to our current method, the SAND balloon catheter is less widely available and more expensive compared to the balloon trocar.