What is the most likely diagnosis for a pediatric patient presenting with an abdominal mass and hypertension?

Wilms Tumor is the Most Likely Diagnosis

In a pediatric patient presenting with an abdominal mass and hypertension (BP 150/100), Wilms tumor is the most likely diagnosis, as hypertension occurs in approximately 25% of Wilms tumor cases and is significantly more common than in neuroblastoma or hepatoblastoma. 1

Clinical Presentation Supporting Wilms Tumor

The combination of abdominal mass with significant hypertension strongly favors Wilms tumor:

• Abdominal mass is the most common presenting feature of Wilms tumor, occurring in 89% of cases 1
• Hypertension occurs in approximately 25% of Wilms tumor patients at presentation 1
• The hypertension in Wilms tumor can be severe enough to cause secondary complications including dilated cardiomyopathy 2, 3

The mechanism of hypertension in Wilms tumor involves:

• Renin secretion by the tumor itself, leading to substantially increased plasma renin activity 3
• Compression of renal vasculature by the tumor mass 2
• The hypertension typically normalizes after tumor removal, confirming its tumor-related etiology 2, 3

Why Not Neuroblastoma or Hepatoblastoma

While neuroblastoma can present with abdominal mass, hypertension is less characteristic and less frequent compared to Wilms tumor 1. Neuroblastoma more commonly presents with:

• Catecholamine-related symptoms (flushing, sweating)
• Metastatic disease patterns (bone, bone marrow)
• Elevated urinary catecholamines

Hepatoblastoma surveillance focuses on AFP monitoring rather than blood pressure abnormalities, as hypertension is not a typical presenting feature 4. Hepatoblastomas are detected through:

• Elevated AFP levels
• Hepatic mass on ultrasound
• Absence of renal origin

Diagnostic Approach

Ultrasound is the optimal initial screening tool for detecting renal masses in children, as it is widely available, lacks ionizing radiation, and can be performed without sedation 4. The workup should include:

• Abdominal ultrasound to confirm renal origin of the mass 1
• Doppler ultrasound to evaluate inferior vena cava for tumor extension 1
• Blood pressure monitoring, as the hypertension severity can guide urgency of intervention 2
• Echocardiography if severe hypertension is present (BP 150/100 qualifies), to assess for hypertensive cardiomyopathy 2, 3

Critical Management Considerations

The presence of significant hypertension (150/100) in a pediatric patient with Wilms tumor requires urgent evaluation and treatment, as it can lead to cardiac complications including dilated cardiomyopathy with reduced ejection fraction 2, 3.

• Antihypertensive therapy should be initiated promptly while diagnostic workup proceeds 2
• Cardiac function assessment via echocardiography is indicated given the severe hypertension 2, 3
• Blood pressure and cardiac function typically normalize after tumor removal and chemotherapy 2, 3

For patients with confirmed Wilms tumor and genetic predisposition syndromes (WT1, Beckwith-Wiedemann, DICER1), renal ultrasound surveillance every 3 months is recommended 5, though this applies to ongoing surveillance rather than initial diagnosis.