Neuroblastoma: Case

Framing the case

This two-year-old girl has the classic presentation of a metastatic neuroblastoma. The firm, irregular abdominal mass that crosses the midline, the irritability and the fever, the periorbital ecchymosis of the orbital metastasis, and the mild hypertension of the catecholamine secretion together make the diagnosis, and the framework that organises the case is the International Neuroblastoma Risk Group staging system and the risk stratification by the MYCN amplification. The first priority is the confirmation of the catecholamine secretion and the staging of the disease extent. ^[1][2]

Confirming the diagnosis

The urinary catecholamine metabolites are the first-line confirmation, and the measurement of the vanillylmandelic acid and the homovanillic acid in a random urine sample, corrected for the creatinine, confirms the diagnosis in over ninety percent of neuroblastomas. The ultrasound confirms the abdominal mass and its origin from the adrenal gland rather than the kidney, and the contrast-enhanced magnetic resonance imaging defines the anatomy, the extension across the midline and the image-defined risk factors. The iodine-123 metaiodobenzylguanidine scan is the functional imaging that maps the disease extent, and the MIBG scan is positive in over ninety percent of neuroblastomas. ^[1][4]

Staging and risk stratification

The staging follows the International Neuroblastoma Risk Group system. The magnetic resonance imaging shows the large right adrenal mass extending across the midline and encasing the aorta and the inferior vena cava, which are the image-defined risk factors that assign the L2 stage. The iodine-123 MIBG scan shows the uptake in the primary mass, the orbital metastasis and the bone marrow, which assigns the M stage for the distant metastatic disease. The bone marrow aspirate and trephine biopsy confirm the marrow involvement with the clumps of the small round blue cells. The percutaneous core biopsy of the primary tumour is sent for the histology and the molecular analysis, and the fluorescence in situ hybridisation shows the MYCN amplification with more than ten copies of the gene per cell. ^[2][5]