Giant Congenital Ovarian Cyst Presenting as an Abdominal Mass

Abstract

Adnexal masses are uncommon in children but are increasingly recognized due to advancements in diagnostic facilities. Such masses in the pediatric population often raise concerns about malignancy. Typically, these masses are small and can resolve spontaneously; however, larger ones can pose a diagnostic dilemma due to their signs and symptoms, requiring clinicians to be particularly vigilant. Simple ovarian cysts are seen in 1 in 2500 live births. They are commonly diagnosed prenatally as intra-abdominal masses by ultrasonography. While there are no established guidelines for management, larger cysts are generally managed surgically (either open or laparoscopic) with the aim of protecting the ovaries and ensuring future fertility. Herein, we present a case of an unusually large congenital ovarian cyst in a newborn that mimicked an abdominal mass, leading to respiratory compromise.

Background

Congenital ovarian cysts are a rare pathology that can be diagnosed during antenatal ultrasound. They are benign and develop due to the enlargement of normal follicles during the third trimester or early neonatal period. ¹ These cysts generally have a good prognosis, especially if they are isolated, unilateral, and unilocular. ¹ While there are numerous differential diagnoses, a simple ultrasonography can establish the diagnosis. ² Before the use of ultrasonography, larger cysts were only detected during examination, however, detection of ovarian cysts has been risen significantly as the increase use of prenatal ultrasonography. ³ Management poses a dilemma as some are asymptomatic but poses a high rate of complications like torsion and metaplasia. The etiopathogenesis remains unclear, but theory states that maternal or placental hormone stimulation is thought to be the cause of fetal ovarian cysts. ³

In this report, we present a case of a newborn female with marked abdominal distention causing difficulty in breathing. The diagnosis was confirmed using an abdominal CT scan, and the condition was managed surgically with successful recovery and relief of symptoms.

Case Presentation

A female baby was delivered via cesarean section due to suspected duodenal atresia identified on antenatal ultrasound, polyhydramnios, and poor progress of labor. The amniotic fluid index was calculated at 28 cm. The baby weighed 3300 g and was transferred to the neonatal ICU for oxygen support due to mild breathing difficulties. No convulsions were reported. The mother’s antenatal visits were uneventful, with normal glycemic control and blood pressure throughout her pregnancy.

On examination, the baby had mild peripheral cyanosis and was on 1 L/hour oxygen support but was not dyspneic or jaundiced. She exhibited mild chest indrawing but had good air entry bilaterally. Her abdomen was symmetrically distended without superficial veins. The umbilical cord was clamped properly and clean, and bowel sounds were audible. She had passed meconium, and other systems were essentially normal on examination.

The baby was kept nil by mouth and placed on maintenance fluids. An abdominal ultrasonography revealed a large peritoneal cyst displacing the bowels to the left side. A plain abdominal X-ray showed right-sided abdominal opacification with bowel loops on the left (Figure 1). Both the plain chest X-ray and echocardiogram were normal. Laboratory investigations were within normal limits, with a hemoglobin level of 17.1 g/dL and serum creatinine of 58 µmol/L. A non-contrast abdominal CT scan subsequently confirmed the presence of a large peritoneal cyst measuring 8.6 cm × 8.5 cm × 6.0 cm, which was pushing the bowels to the left (Figure 2). Due to its large size, the exact origin of the cyst was not certain.

Figure 1.

Abdominal X-ray showing abdominal mass pushing the bowels to the left side (red arrows)

Figure 2.

Abdominal-pelvic CT-scan ((a) axial, (b) coronal and (c) sagittal) showing huge cystic mass (ovarian cyst) arising from the pelvis pushing intra-abdominal viscera cranially and towards the left.

After counseling the parents and obtaining consent for surgery, a laparotomy was planned. A transverse incision was made in the abdomen, revealing a large right ovarian cyst measuring 12 cm in its largest diameter, occupying approximately two-thirds of the peritoneal cavity. The cyst was excised intact, without rupture, while preserving the fallopian tube and ovary (Figure 3). The rest of the abdominal organs were inspected intra-operatively and were normal, including patent gastrointestinal tract. Blood loss was minimal, and the surgery was completed in 50 minutes by a general surgeon. The cyst was sent for histological analysis, which concluded it as a benign ovarian follicular cyst.

Figure 3.

Operative photograph showing huge ovarian cyst (a) and excised whole (b).

The baby recovered well from anesthesia and continued to fare well postoperatively, tolerating oral feeds with vital signs remaining within normal limits. Serum α-fetoprotein was 2.2 ng/mL (0-10 ng/mL) and serum β-hCG level was 39 IU/L (10-50 IU/L) hence within normal ranges. The baby was discharged on day 3 and was reviewed 3 weeks later, showing no symptoms or signs of complications.

A follow-up review 2 months later confirmed that all laboratory tests, including α-fetoprotein and β-hCG levels, remained within normal ranges.

Discussion

Fetal and neonatal ovaries are usually dormant, but follicular cysts may occur. The proposed etiopathogenesis behind this is exposure to fetal pituitary gonadotropins, placental human chorionic gonadotropins, and maternal estrogen stimulates fetal ovaries and follicle production. ² The estimated incidence of these ovarian cysts is 1 in 2625 live births, and less than 2 cm cysts are found in about 34% of neonates. In contrast, ovarian cysts have been found in 2% to 3% of girls under 8 years who have had ultrasonography for any other reasons.^{4 -6} Many are reported to resolve spontaneously, especially smaller, simple ones, however, variability do exist in the evaluation and management options of these lesions. They can be associated with complications like torsion and hemorrhage, and risk increases with size.^4,5 Ovarian malignancies are usually uncommon in children but should be considered especially with complex cysts, other common being germ-cell tumors. ⁵

These cysts can be classified into simple and complex according to Nussbbaum’s classification; simple are anechoic with thin walls whereas complex cysts are 1. Partially anechoic with debris 2. Partially anechoic with retracting clot 3. Septate with or without internal echoes, 4. Solid. ⁶ In the presented case, the cyst was simple but CT-scan was done because of the big size and to ascertain its origin. Our differentials were mesenteric cyst, choledochal cyst, renal cyst, or urachal cyst. Other associated anomalies are congenital pyloric stenosis, hydrocephalus, agenesis of corpus callosum, and fetal hypothyroidism. ⁷ Clinically these were ruled out in the index case hence no further investigations were needed. These fetal cysts are located in the abdomen rather than the pelvis, as the fetal ovary remains an abdominal organ due to the small size of the pelvis. ⁷ Consequently, our newborn presented with abdominal distention and respiratory compromise due to the pressure effect. Fetal cysts have also been associated with maternal diabetes, toxemia, and rhesus isoimmunizations, likely due to the increase in human chorionic gonadotropin (hCG). ⁸ Polyhydramnios occurs in 18% of the cases, especially when the cyst is usually more than 6 cm and compresses the gastrointestinal tract as evident in the index case. ⁹

In most cases reported the cysts have been small and resolve spontaneously as maternal hormones decreases.^8,9 In 44% they occur on the left side, 31% on the right and 25% bilateral. There is ongoing controversy on the management of these cysts. Smaller (<2 cm) asymptomatic can be managed conservatively with serial ultrasound while bigger ones need to be excised surgically as they are at risk of torsion or compression to other organs as in our case. Some suggest needle aspiration but recurrence rates are higher. ⁹ Ultrasound guided aspiration carries less risks but requires multiple procedures due to the tendency of recurrences. Another disadvantage includes the absence of histological diagnosis. ¹⁰

Some literature reports that larger cysts (approximately 8 cm) may regress spontaneously. Therefore, if clinicians opt for conservative management based on the clinical signs and symptoms, it is crucial for guardians and parents to cooperate and be educated on recognizing adverse symptoms. This ensures compliance with the long-term follow-up plan and timely intervention if necessary. ¹⁰ Enríquez et al ³ conclude in their article that surgery should be reserved for larger ovarian cysts causing clinical manifestations due to their size, and those not involuting spontaneously. Neonatal laparoscopy is increasing in popularity among pediatric surgeons as it equally serves as a diagnostic and therapeutic roles at the same time maintaining cosmesis. On the contrary, documented complications include cardio-respiratory compromise and post-operative hypothermia from the gas inflation. ¹⁰ In our case, we did not have the surgical expertise and the newborn was already in respiratory distress.

In this case report, we present a case of an uncommonly large congenital ovarian cyst in a newborn who exhibited gross abdominal distention and subsequent respiratory distress. Due to its very large size, a CT scan could not delineate its origin; however, the diagnosis was made intraoperatively, revealing that the cyst arose from the newborn’s right ovary. The cyst was successfully excised whole while preserving the fallopian tube and ovarian tissue. Histology confirmed it to be a simple cyst with no features of malignancy.

Early diagnosis of such cysts can be made during prenatal ultrasonography, aiding in planning management options. While there are no established management guidelines in the literature, we recommend that clinicians individualize management options based on the clinical characteristics of their patients, the socio-demographic context of the guardians, and the availability and level of local expertise. Clinicians based in smaller, remote health centers are advised to refer such cases to tertiary-level health facilities for appropriate management and follow-up planning.

Conclusion

Congenital fetal ovarian cysts are rare but can be detected early through antenatal ultrasound scans. Although few cases in the literature report cysts larger than 10 cm, this case represents one of the largest documented. When encountering cystic lesions of this size, it is crucial to consider various differential diagnoses. Advanced radiological modalities may be necessary to accurately identify the condition, particularly when the lesions are unusually large or involve adjacent systems and viscera.