A 3-year-old girl is brought to the office for a health supervision examination. The patient has met developmental milestones appropriately and is up to date on immunizations. Temperature is 36.6 C (97.9 F), blood pressure is 156/96 mm Hg, and pulse is 100/min. She appears well nourished. On abdominal palpation, there is mild tenderness in the right lower and upper quadrants and a palpable mass in the right abdomen. Ultrasound reveals a 12-cm, heterogenous, solitary mass arising from the upper pole of the right kidney. Which of the following is the most likely diagnosis for this patient?

Question

A 3-year-old girl is brought to the office for a health supervision examination.  The patient has met developmental milestones appropriately and is up to date on immunizations.  Temperature is 36.6 C (97.9 F), blood pressure is 156/96 mm Hg, and pulse is 100/min.  She appears well nourished.  On abdominal palpation, there is mild tenderness in the right lower and upper quadrants and a palpable mass in the right abdomen.  Ultrasound reveals a 12-cm, heterogenous, solitary mass arising from the upper pole of the right kidney.  Which of the following is the most likely diagnosis for this patient?

Quizplus · Accepted Answer

11ec25c8_d734_79dc_bc81_534dd0d148db_MD0003_00 Wilms tumor (nephroblastoma) is a renal cancer arising from the metanephros and is one of the most common causes of malignant abdominal masses in young children. The tumor typically occurs sporadically but can be associated with certain syndromes (eg, WAGR [Wilms tumor, Aniridia, Genitourinary abnormalities, mental Retardation], Beckwith-Wiedemann syndrome). Typical presentation involves a child age 2-5 with a unilateral abdominal mass (ie, a mass that does not cross the midline). The mass is often asymptomatic; however, some patients may have associated abdominal pain or hematuria. Hypertension can also occur (as in this patient) due to renin secretion by tumor cells and/or compression of renal vasculature by the mass. Abdominal ultrasound is the first step in evaluation of an abdominal mass; subsequent abdominal CT scan or MRI can further characterize the extent of the tumor. Pathology during surgical excision or biopsy is diagnostic. (Choice A) Neuroblastoma is another common malignant abdominal mass. However, it typically presents in children age <2. In addition, the mass arises from neural crest cells (eg, adrenal glands), not from the kidney (as in this patient). Finally, although hypertension can occur with neuroblastoma, it is less common than with Wilms tumor. (Choice B) Pheochromocytoma is a catecholamine-secreting tumor that can cause episodic headache, tachycardia, sweating, and/or hypertension. The mass arises from the adrenal glands, rather than the kidney. (Choice C) Polycystic kidney disease presents with bilateral flank masses due to enlarged cystic kidneys. In contrast, this patient's mass is unilateral, and ultrasound shows no cysts. (Choice D) Renal cell carcinoma is a renal malignancy that presents in adolescents and adults with flank pain, hematuria, and a mass. This patient's young age makes Wilms tumor much more likely. Educational objective: Wilms tumor (nephroblastoma) is the most common renal malignancy in children. It typically presents with an asymptomatic unilateral abdominal mass. References: An approach to renal masses in pediatrics. (http://www.ncbi.nlm.nih.gov/pubmed/25452658) The prognostic significance of hypertension at diagnosis in children with Wilms tumor. (http://www.ncbi.nlm.nih.gov/pubmed/28251221)

A 3-Year-Old Girl Is Brought to the Office for a Health