Antenatal ultrasonographic detection of a rare intrauterine unilateral renal mass

Congenital Wilms’ tumor is an exceptionally rare variant of nephroblastoma, diagnosed either in utero or within the first 30 days of life. Its clinical presentation and biological behavior may differ from the typical pediatric form, requiring a specialized approach to diagnosis and treatment. We present a case of a full-term newborn with a unilateral congenital Wilms’ tumor, initially detected during prenatal ultrasonography as an abdominal mass. Postnatal evaluations, including contrast-enhanced computed tomography (CT) and laboratory studies, confirmed the presence of a renal tumor confined to the left kidney. The patient underwent surgical resection via nephrectomy on day seven of life. Histopathological examination revealed Wilms’ tumor stage II based on surgical and pathological findings. Postoperative recovery was uneventful, and the patient was started on adjuvant chemotherapy according to pediatric oncology protocols. This case underscores the value of early prenatal detection, multidisciplinary management, and individualized therapeutic planning in achieving favorable outcomes for neonates with congenital Wilms’ tumor.