Chapter 34: The boy who fell off his bike

A mother heard the cry of her 3-year old and found that he had fallen onto the handle bars of his tricycle. He had right-sided abdominal pain. She brought him to the paediatric A&E. He was found to be anaemic (Hb10) and an abdominal ultrasound was performed.

There was a 10 cm x 8 cm x 7 cm mass between the right kidney and the right lobe of the liver. It was hyperechoic and heterogeneous with some vascularity within it. A provisional diagnosis of haematoma or adrenal haemorrhage was suggested.

He had an urgent out of hours CT scan with intravenous contrast.

• 1. What does the CT scan show?

  Show Answer

  Correct answer:
  
  Large heterogeneous suprarenal mass containing internal vascularization, displacing bowel but with no obvious calcification.

The radiological findings are consistent with a neuroblastoma. The most common finding in neuroblastoma is a large, irregular abdominal mass that characteristically crosses the midline. Neuroblastomas may present with non-specific symptoms such as weight loss, failure to thrive, fever and pallor, especially if widespread metastases are present. Plain abdominal X-ray may show calcification: this occurs in 70% of neuroblastoma and 15% of Wilms’ tumours. Other diagnostic investigations for neuroblastoma include 131-I-labelled meta-iodobenzyl guanidine (MIBG) scan and blood or urinary catecholamines including vanillylmandelic acid (VMA), serum neuron-specific enolase (NSE) and ferritin.

His urinary excretion of the catecholamine metabolites VMA and homovanillic acid (HVA) per mg of excreted creatinine were raised. A biopsy confirmed the diagnosis of neuroblastoma.

Neuroblastomas are divided into three risk groups (low-risk, intermediate-risk, and high-risk) based on:

1. Age
2. International neuroblastoma staging system (INSS) stage
3. International neuroblastoma pathologic classification (INPC)
4. Ploidy
5. Amplification of the MYCN oncogene within tumour tissue

He had intermediate risk neuroblastoma and was treated with surgery followed by four cycles of adjuvant combination chemotherapy. He achieved a complete remission of his neuroblastoma and was ready to start school at 4 years old.