# A rare case of fetal bilateral Wilms' tumor in horseshoe kidney: A case report

## TL;DR

A rare case of fetal bilateral Wilms' tumor in a horseshoe kidney is reported, highlighting the challenges in prenatal diagnosis and management.

## Contribution

This case report presents a rare fetal bilateral Wilms' tumor in a horseshoe kidney, emphasizing prenatal imaging's role in diagnosis.

## Key findings

- Fetal bilateral Wilms' tumor was diagnosed in a horseshoe kidney via prenatal ultrasound and confirmed post-termination.
- Prenatal imaging played a critical role in identifying severe congenital defects and guiding clinical decisions.
- Histopathology confirmed the presence of triphasic Wilms' tumor in the fused kidneys.

## Abstract

Wilms' tumor is the most common malignant kidney tumor in children. The horseshoe kidney is the most common renal fusion malformation. However, Wilms' tumor is rarely identified in horseshoe kidney patients. The incidence of horseshoe kidney is about 1 in 400 cases. Wilms' tumor or Nephrogenic rests can occur in both kidneys, termed bilateral disease, found in only 5–8 % of cases. Management of bilateral Wilms' tumor presents a major clinical challenge in terms of maximizing survival, preserving renal function, and understanding underlying genetic risk.

Our case is a 28-year-old primigravid female patient, who came for the complaint of decreased abdominal girth and decreased fetal moment. Obstetric ultrasound concluded severe oligohydramnios + renal mass and safe termination was done. Subsequent examinations of the autopsy revealed bilateral Wilms tumor in horseshoe kidney.

Ultrasound is used to diagnose horseshoe kidneys, whereas Computed tomography and magnetic resonance imaging are often used for staging purposes. Histopathological analysis is the current gold standard for diagnosing Wilms' tumor. Surgery, chemotherapy, and radiotherapy are also used to treat Wilms' tumor.

Fetal Wilms' tumor (WT) is extremely rare, but advances in fetal imaging have led to increased detection of such cases. Managing these cases remains challenging due to the complexity of treatment and the needed for preserving renal function. Prenatal ultrasound is an essential diagnostic tool for early detection and intervention.

•Rare Case: Fetal bilateral Wilms' tumor in a horseshoe kidney diagnosed in a 28-year-old primigravid patient from Sidama, Ethiopia, emphasizing challenges in managing congenital anomalies during pregnancy.•Clinical Features: Decreased fetal movement, severe oligohydramnios, and abdominopelvic mass on prenatal ultrasound noted.•Diagnosis/Intervention: Prenatal suspicion of nephroblastoma; medical termination due to severe congenital defects, with histopathologic confirmation.•Histopathology: Autopsy revealed fused kidneys (horseshoe) with multicystic lesions and triphasic Wilms' tumor on microscopy.•Outcome: Uncomplicated maternal recovery; discharged with follow-up guidance.•Significance: Underscores prenatal imaging role in diagnosing rare renal tumors, particularly in resource-limited settings.

Rare Case: Fetal bilateral Wilms' tumor in a horseshoe kidney diagnosed in a 28-year-old primigravid patient from Sidama, Ethiopia, emphasizing challenges in managing congenital anomalies during pregnancy.

Clinical Features: Decreased fetal movement, severe oligohydramnios, and abdominopelvic mass on prenatal ultrasound noted.

Diagnosis/Intervention: Prenatal suspicion of nephroblastoma; medical termination due to severe congenital defects, with histopathologic confirmation.

Histopathology: Autopsy revealed fused kidneys (horseshoe) with multicystic lesions and triphasic Wilms' tumor on microscopy.

Outcome: Uncomplicated maternal recovery; discharged with follow-up guidance.

Significance: Underscores prenatal imaging role in diagnosing rare renal tumors, particularly in resource-limited settings.