Paraovarian cysts (POCs), usually located along the fallopian tube, arise from the mesosalpinx or the broad ligament. They are cystic structures filled with serous fluid [2], and regarding their embryological origin, 68% are mesothelial, 30% are embryonic vestiges of paramesonephric (Müllerian) ducts and 2% of mesonephric ducts [1, 6]. Müllerian-derived structures are lined by a secretory epithelium, responsible for the cystic dilation; they are also hormonal influenced, which explains the incidence in postpubertal patients and why they can reach huge sizes [6].
When a POC is located near the fimbria, pedunculated and smaller than 2 cm, it is usually considered to be a cystic hydatid of Morgagni [4]. Regarding the sizes, 95% of POCs were found to be less than 2 cm in diameter [3], but they can range from 1 to 8 cm [4]. Cysts bigger than 10 cm are extremely uncommon and are usually documented in case reports [2].
Diagnosis of paraovarian cysts is challenging, only 30 - 44% of them being identified preoperatory [2]. Mostly asymptomatic, they are usually discovered during abdomino-pelvic imaging investigations or surgery for other pathologies [3]. Unspecific symptoms like recurrent pain, increase in abdominal volume or feeling of weight in the low abdomen, occur as the cyst slowly grows [5]. Our patient tolerated the tumor extremely well, without any symptoms, except weight gain complaints. Like many other conditions (e.g., mesenteric cyst, urachal cyst, Meckel diverticulum) POC may also become symptomatic when complicates with adjacent organs compression, intracystic hemorrhage, perforation or torsion, the incidence of malignancy being very low [7]. In such cases patients can present with acute abdominal pain, vomiting or nausea [1]. Although in children the incidence of POC is lower than in adults, complication rate seems to be higher, the most frequent complication being the torsion. The cause may be the longer pelvic ligaments in pediatric ages, especially the infundibulopelvic ligament [1]. Torsion could only involve the cyst itself, or the cyst with the fallopian tube and the ovary. Another risk factor for torsion appears to be the cyst diameter greater than 5 cm [6]. Regarding the malignancy, the literature has reported an incidence of 2.9%, mostly in adults patients [8].
Imaging investigations consist primarily in abdomino-pelvic ultrasound, which may diagnose a cystic mass, and establish its location and size, but can misdiagnose its origin. Many reports showed that POCs are diagnosed as ovarian cysts or other types of cystic masses (mesenteric cyst, lymphangioma) [1, 6]. Computed tomography or magnetic resonance imaging (MRI) seem to be more accurate in showing a delineation between the ovary and the unilocular cystic lesion [1]. The MRI is preferred, because it avoids radiation damages, which is essential especially in young girls [9]. In our case, we tried to perform a MRI, but the patient had a claustrophobic attack. All three US, MRI, and CT may show an anechoic unilocular homogenous cyst, round or oval, well-defined, separated from the ipsilateral ovary; they also can reveale malignancy signs like intracystic papillary projections. However, to diagnose a cyst is easy, but as it also was in our case, to diagnose the cyst’s origin in the broad ligament remains difficult. The diagnosis of certainty is usually established at surgery, respectively by histological examination [1, 4, 8].
Once diagnosed or incidentally found, POCs should be excised, due to their constant growth and torsion risk [3, 8]. Pediatric anesthesiologists prefer the inhalational induction with sevoflurane because of its rapid action, pleasant odor and absence of airways irritation [10]. Open surgery, through a midline or a Pfannenstiel incision, has been the most widely used approach in cases of POC [5, 9, 11]. Removal of a giant POC sometimes requires associated oophorectomy or tubal excision, when malignancy signs or torsion are present [1]. Lately the mini-invasive approach tends to become the procedure of choice, even in pediatric population, its advantages being widely recognized. Limiting factors for laparoscopy are the giant size of the mass or the presence of malignity signs. Ovary-sparing procedures must become the gold standard for the surgical management of POCs in young patients [1, 4]. Due to the giant size of the tumor we chose the open approach, and even so, we had to partially evacuate the content by punction, before cystectomy.