Wilms Tumor is the Most Likely Diagnosis
In a pediatric patient presenting with an abdominal mass and severe hypertension (BP 150/100 mmHg), Wilms tumor is the most likely diagnosis among the options provided. 1, 2
Clinical Reasoning
Why Wilms Tumor (Answer A)
Hypertension is a characteristic feature of Wilms tumor, occurring through two mechanisms: renal parenchymal disease and renin-mediated hypertension from the tumor's renal origin 1
The classic triad of Wilms tumor includes abdominal mass, hypertension, and hematuria, with abdominal mass being the most common presenting feature 3
Wilms tumor is the most common renal malignancy in childhood, primarily occurring between ages 2-5 years 3
Severe hypertension can occur with Wilms tumor, with documented cases presenting with blood pressures as high as 180-200/120 mmHg, similar to this patient's presentation 4
Why Not Neuroblastoma (Answer B)
Neuroblastoma causes hypertension less frequently compared to Wilms tumor 1
Neuroblastoma typically presents with elevated urinary catecholamines and catecholamine-related symptoms (flushing, sweating, paroxysmal hypertension), which are not mentioned in this case 1, 2
Neuroblastoma more commonly presents with bone/bone marrow metastases rather than isolated abdominal mass with hypertension 1, 2
Why Not Hepatoblastoma (Answer C)
Hypertension is NOT a characteristic feature of hepatoblastoma 1, 2
Hepatoblastoma presents with elevated AFP levels and hepatic mass on ultrasound, not typically with hypertension 1, 2
Immediate Diagnostic Workup Required
Abdominal ultrasound with Doppler should be performed immediately to confirm renal origin of the mass and evaluate for inferior vena cava tumor extension 1, 2
Urinalysis, serum creatinine, and electrolytes to assess renal function 1
Chest imaging to evaluate for pulmonary metastases, as Wilms tumor commonly metastasizes to lungs 3
Urgent Management Considerations
Antihypertensive therapy should be initiated immediately given the severe BP elevation (150/100 mmHg), with calcium channel blockers or ACE inhibitors as first-line agents 1
Avoid tumor biopsy - the North American Children's Oncology Group recommends upfront nephrectomy for unilateral tumors without pre-operative biopsy, as biopsy risks tumor spillage and upstaging 2
Assess the contralateral kidney for bilateral disease, which occurs in a significant subset of Wilms tumor patients 2
Critical Pitfall to Avoid
Do not dismiss severe hypertension in a child with an abdominal mass as primary hypertension. In younger children (especially under age 6), secondary causes of hypertension—particularly renal parenchymal disease and renal masses—account for 34-79% of hypertension cases 5, 6. The combination of abdominal mass and hypertension in a pediatric patient should immediately trigger evaluation for Wilms tumor, as delayed diagnosis can lead to disease progression and worse outcomes 3, 4.