Neonatal ovarian cyst

Clinical History

A two-day-old female was found to have a 9 cm abdominal mass on antenatal US scanning. This was confrimed by doing a postnatal US scan.

Imaging Findings

An antenatal US scan performed on a two-day-old female revealed the presence of an abdominal mass. The post delivery US revealed a 9 cm abdominal cyst with an anechoic wall, which was thought to be ovarian in origin. The neonate was well at birth but started vomiting after feeds. On day 3, a left ovarian cystectomy was performed by a laparotomy.

Discussion

Neonatal ovarian cysts are known to be of follicular origin and result from disordered folliculogenesis. Microcysts (less than a size of 9 mm) have been reported to be present in 82% of patients aged between 1 and 90 days, whereas macrocysts (greater than 9 mm) have been reported to be present in 20% of patients in that same age group. It has been suggested that excessive secretion of placental and maternal hormones is responsible for the development of cysts in neonates. There is an increased incidence of cysts in infants of mothers with diabetes, toxemia and rhesus immunization, as well as in hypothyroid infants. Complications of cysts include torsion, haemorrhage and cyst rupture. Cysts may exert pressure on the lungs, bowel and the urinary tract. Maternal complications include polyhydramnios and vaginal dystocia, both arising as a result of the rupture of large cysts. The sonographic appearances of cysts vary depending on the size and on whether the cyst is a complicated one or not. Uncomplicated cysts appear as round, homogeneous anechoeic masses. A complicated cyst is generally dishomogeneous, contains a fluid-debris interface, a retracting clot or septa or is completely filled with echoes resembling a solid mass. In a retrospective study of 23 cystic lesions, the “daughter cyst” sign (small cyst either protruding into the lumen or lying along the outer wall of the cyst) was found in 9 out of 11 ovarian cysts and is believed to be a specific sonographic finding for an ovarian cyst. The differential diagnosis of an ovarian cyst includes a mesenteric, enteric or urachal cyst, anterior meningocoele, hydrometrocolpos, lymphangioma and ovarian neoplasms. The management of a neonatal ovarian cyst depends on the size and sonographic appearances. After birth, the decrease in hormonal stimulation will lead to cyst regression in most cases. Therefore, cysts less than 4 cm in dimensions are usually observed using serial ultrasonography. Cysts larger than 4 cm in size are associated with a greater risk of torsion, and most surgeons advocate surgical removal (which can be performed laporoscopically) or by needle aspiration (either in utero or after birth). If surgery is to be performed it is necessary to try and preserve as much gonadal tissue as possible for future endocrine and fertility functioning.

Differential Diagnosis List

Final Diagnosis

Left ovarian cyst.

URL:	https://eurorad.org/case/988
DOI:	10.1594/EURORAD/CASE.988
ISSN:	1563-4086