Surgery MCQs Q3

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PEDIATRICS • ONCOLOGY

An 18-month-old child is brought to the emergency department with failure to thrive, intermittent fever, and occasional blood in the diaper. On abdominal examination, a firm, non-tender renal mass is palpated.

What is the most likely diagnosis?

A Transitional cell tumor of the bladder

B Nephroblastoma

C Angioma of the renal artery

D Adenocarcinoma of the kidney

E Transitional cell tumor of the ureter

Wilms Tumor (Nephroblastoma). This is the most common renal malignancy in children. The classic presentation includes an asymptomatic abdominal mass, fever, and hematuria in a toddler.

Decoding Clue

1

CLUE "Infant (18 months) + abdominal/renal mass"

TRANS Most renal masses in toddlers are either Wilms Tumor or Neuroblastoma. Renal origin favors Wilms.

2

CLUE "Occasional blood in diaper"

TRANS Hematuria is present in ~25% of cases and strongly suggests a renal parenchyma malignancy.

Differential Breakdown

A & E. Transitional Cell Tumors: Typical of adults (smokers, dye workers). Extremely rare in infants.

C. Angioma: Usually benign and smaller; doesn't typically present as a large firm mass with failure to thrive.

D. Adenocarcinoma (RCC): The primary renal cancer of adults (50-70 years). In children, Nephroblastoma is vastly more common.

🧠 Pediatric Renal Tumors

Feature	Wilms Tumor	Neuroblastoma
Mass Character	Smooth, stays in flank	Irregular, crosses midline
Systemic Features	HTN, Hematuria	Opsoclonus-Myoclonus
Calcification	Rare	Common (on CT)

High-Yield Challenges

Challenge #1: Physical Exam

Why is vigorous palpation contraindicated in a suspected Wilms tumor?

Answer: Risk of capsule rupture and peritoneal seeding/hemorrhage.

Challenge #2: Genetics

What does the "A" stand for in WAGR syndrome?

Answer: Aniridia (absence of the iris).

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