Wilms Tumor is the Most Likely Diagnosis
A pediatric patient presenting with an abdominal mass and hypertension (BP 150/100 mmHg) most likely has Wilms tumor, as this combination is the classic presentation of this renal malignancy. 1, 2
Diagnostic Reasoning
Why Wilms Tumor (Option A) is Correct
- Hypertension is a hallmark feature of Wilms tumor, occurring through two mechanisms: renin-mediated hypertension from the tumor's renal origin and renal parenchymal disease 1
- The combination of abdominal mass plus hypertension is the characteristic presentation pattern, with hypertension occurring in a substantial proportion of cases at diagnosis 2, 3
- Wilms tumor is the most common renal malignancy in children, representing over 90% of all pediatric kidney tumors, typically occurring between ages 2-5 years 2, 4
- The blood pressure elevation of 150/100 mmHg represents severe hypertension requiring immediate evaluation, which is consistent with the acute presentation of Wilms tumor 1, 2
Why Neuroblastoma (Option B) is Less Likely
- While neuroblastoma can present with abdominal mass and hypertension, hypertension occurs less frequently compared to Wilms tumor 1
- When hypertension does occur with neuroblastoma, it typically presents with additional catecholamine-related symptoms (flushing, sweating, irritability) and elevated urinary catecholamines (VMA, HVA) 1, 5
- Neuroblastoma more characteristically presents with bone/bone marrow metastases rather than isolated abdominal mass with hypertension 1
Why Hepatoblastoma (Option C) is Incorrect
- Hypertension is not a characteristic feature of hepatoblastoma 1, 5
- Hepatoblastoma presents with elevated AFP levels and hepatic mass on ultrasound, but the association with hypertension is absent 1, 6
Immediate Diagnostic Workup
Perform abdominal ultrasound with Doppler immediately to confirm renal origin of the mass and evaluate for inferior vena cava tumor extension 1, 6
Additional essential initial tests include:
- Urinalysis, serum creatinine, and electrolytes to assess renal function 1
- Complete blood count and comprehensive metabolic panel 5
Blood Pressure Management
Initiate antihypertensive therapy immediately given the severe BP elevation (150/100 mmHg), using calcium channel blockers or ACE inhibitors as first-line agents 1
Important Caveat About ABPM
- While ambulatory blood pressure monitoring (ABPM) can confirm true hypertension versus white coat hypertension, patients with higher office BP levels (like 150/100) are more likely to be truly hypertensive 7
- Given the severe elevation and presence of an abdominal mass, immediate action is warranted rather than waiting for ABPM confirmation 1
Surgical Considerations
Do not perform pre-operative biopsy for suspected unilateral Wilms tumor, as the North American Children's Oncology Group recommends upfront nephrectomy without biopsy to avoid tumor spillage and disease upstaging 6