A 2-year-old boy is brought to the emergency department by his parents after they discovered an abdominal mass while giving him a bath this evening. The mass does not appear to be causing the patient pain. He has had constipation for the last 2 weeks, which the parents have treated with stool softeners. His parents are also concerned that his face and neck become red and that his palms perspire several times a day even when he is cold. The patient has also had decreased energy and a 1.5 kg (3.3 lb) weight loss in the last month despite a normal appetite. He has no chronic medical conditions, has had no surgeries, takes no medications, and has no known allergies. Temperature is 37.2 C (99 F), blood pressure is 140/90 mm Hg, and pulse is 120/min. Physical examination reveals a toddler who appears in no distress. The lungs are clear to auscultation. Heart rate and rhythm are normal; there are no murmurs. The abdomen is soft and nontender; a baseball-sized, nontender, fixed mass is palpable in the right mid-abdomen. Which of the following is the most likely diagnosis for this patient?

Question

A 2-year-old boy is brought to the emergency department by his parents after they discovered an abdominal mass while giving him a bath this evening.  The mass does not appear to be causing the patient pain.  He has had constipation for the last 2 weeks, which the parents have treated with stool softeners.  His parents are also concerned that his face and neck become red and that his palms perspire several times a day even when he is cold.  The patient has also had decreased energy and a 1.5 kg (3.3 lb) weight loss in the last month despite a normal appetite.  He has no chronic medical conditions, has had no surgeries, takes no medications, and has no known allergies.  Temperature is 37.2 C (99 F), blood pressure is 140/90 mm Hg, and pulse is 120/min.  Physical examination reveals a toddler who appears in no distress.  The lungs are clear to auscultation.  Heart rate and rhythm are normal; there are no murmurs.  The abdomen is soft and nontender; a baseball-sized, nontender, fixed mass is palpable in the right mid-abdomen.  Which of the following is the most likely diagnosis for this patient?

Quizplus · Accepted Answer

Explanation: 11ec2b69_bf70_9714_8f63_11a1898464bf_MD0005_00 This child has an abdominal mass, weight loss, and signs of excess catecholamine secretion, concerning for a neuroblastoma, the most common extracranial solid tumor of childhood. Patients typically present in early childhood with a painless mass originating in the adrenal medulla or along the sympathetic chain. Less commonly, large neuroblastomas may compress the bowel (causing constipation), bladder (causing urinary incontinence), or renal artery. Compression of the renal artery can activate the renin-angiotensin system (RAS) and cause hypertension. renin-angiotensin system Neuroblastomas are derived from the cells of primitive sympathetic ganglia and secrete catecholamines (eg, epinephrine, norepinephrine), which contribute to the elevated blood pressure as well as cause flushing and sweating. Elevated urine or serum catecholamine metabolites aid in the diagnosis, and biopsy is confirmatory. (Choice A) Hepatoblastoma may also present in young children with an asymptomatic abdominal mass; however, hypertension, flushing, and sweating are not associated with this tumor. (Choice C) Enlarged kidneys due to polycystic kidney disease can present as an abdominal mass. Hypertension can also result from activation of the RAS similar to neuroblastoma, but no catecholamine release is expected. (Choice D) Rhabdomyosarcoma is a malignant soft-tissue tumor found most commonly in the head and neck region. A painless mass can occur at other sites (eg, bladder, genitourinary tract) but would not cause flushing, sweating, or hypertension as seen in this patient. (Choice E) Wilms tumor is the most common renal malignancy in children and typically presents at age <5 with a unilateral, often painful, abdominal mass as well as hypertension and hematuria. Flushing and sweating are not seen with Wilms tumors. Educational objective: Neuroblastomas are the most common extracranial solid tumors in children and typically present with a painless abdominal mass. Patients may have hypertension due to the mass compressing the renal artery and activating the renin-angiotensin system, and catecholamine hypersecretion can lead to flushing and sweating. References: Neuroblastoma. (http://www.ncbi.nlm.nih.gov/pubmed/27830764)

A 2-Year-Old Boy Is Brought to the Emergency Department by His