Neonatal Abdominal Cysts

Differential considerations for a pelvic mass in a child:

• Duplication cyst: Look for bowel wall signature on ultrasound.
• Ovarian cyst (shown above): Can be seen during the second trimester and persist into infancy. Due to maternal and/or placental hormones or adrenogenital syndrome. Can get large and lead to torsion. A specific finding is the "daughter cyst" sign, representing a follicle in the ovarian cyst. The images above demonstrate a cystic pelvic mass superior to the urinary bladder (B) on prenatal MRI. Neonatal ultrasound shows a complex mass with an internal daughter cyst
• Mesenteric cyst:
• Cystic meconium peritonitis:
• Choledocal cyst:
• Urachal remnant: Urachal cyst or diverticulum
• Renal cyst:
• Mimics: Hydronephrosis, hydroureter, hydrometrocolpos, bowel atresia/obstruction, anterior meningocele.

References

• Lee HJ, Woo SK, Kim JS, Suh SJ. "Daughter cyst" sign: a sonographic finding of ovarian cyst in neonates, infants, and young children. AJR Am J Roentgenol. 2000 Apr;174(4):1013-5.
• Schmahmann S, Haller JO. Neonatal ovarian cysts: pathogenesis, diagnosis and management. Pediatr Radiol. 1997 Feb;27(2):101-5.