Neoplasia USMLE Step 1 Practice Question
A 7-year-old boy presents to the emergency department with his mother who noticed blood in his urine over the past 2 weeks. On examination, he has a palpable left flank mass and his blood pressure is 148/94 mmHg (>95th percentile for age). Laboratory studies show hemoglobin 9.2 g/dL, creatinine 0.9 mg/dL, and elevated plasma renin activity. Abdominal ultrasound reveals a 5.5-cm left renal mass with internal heterogeneity. CT staging shows the tumor is confined to the kidney with no involvement of the renal vein, inferior vena cava, or distant metastases. Histopathology demonstrates a triphasic tumor with blastematous, epithelial, and stromal components. Which of the following is the single most important prognostic factor for this patient's disease-free survival?
Answer choices
- APatient age less than 10 years at diagnosis
- BPresence of gross hematuria as the initial symptom
- CTumor histology (favorable vs. unfavorable) and surgical stageCorrect answer
- DDegree of renin elevation and severity of hypertension
- ETumor size (5.5 cm) at presentation
- FAbsence of metastatic disease at time of diagnosis
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