An Interesting Neonatal Abdominal Mass

Abstract

We present the case of a neonate who was born with an antenatal ultrasound diagnosis of a cystic abdominal mass of uncertain origin. The diagnosis of pelviureteric junction obstruction (PUJO) was obscured by difficulty determining the origin of the extremely large cystic abdominal mass. Sonographically, the kidneys appeared relatively normal, creating a diagnostic dilemma – the hydronephrosis was almost exclusively in an extrarenal pelvis. Additionally, contralateral hydronephrosis secondary to the mass effect further confused the diagnosis. We discuss the differential diagnosis of neonatal cystic abdominal masses and review the literature of giant hydronephrosis.

Key Words: Abdominal mass, neonate, diagnosis, ultrasonography,  ureteropelvic junction obstruction