In rare cases, neuroblastoma can be detected prior to birth, however it is usually found later. About 40 percent of the cases are diagnosed in the first year. If the patient is older than a year and the cells are growing rapidly, they are usually malignant and have spread to other areas such as the lymph nodes, liver, lungs and bones. The older the patient is, the more aggressive the cancer and the poorer the outcome. For this reason, early detection is important.

Diagnosing neuroblastoma usually begins by obtaining a medical history, including family history of disease. The physician will perform a physical examination of the patient’s body with focus on signs of disease, including tumor masses and lumps. Tests that may be performed when neuroblastoma is suspected include:

• Blood tests. Laboratory tests performed on a sample of blood to detect chemical or hormonal imbalances and genetic predispositions for cancer. They may include:
  
• • Catecholamine test. A blood test that measures levels of these hormones secreted by the adrenal glands. High levels of catecholamines may indicate neuroblastoma.
    
    
  • Complete blood count (CBC). A blood test that provides information about all blood cells (red, white and platelets). Low levels of red blood cells (anemia) may be present in neuroblastoma.
    
    
  • Genetic testing. DNA can be checked for the presence of oncogenes and deletions of tumor suppressor genes. Genetic alterations such as these can indicate a genetic predisposition for cancer as well as potential prognosis for survival. Also, there are tests for inherited attributes related to neuroblastoma. Recent research has identified a gene called caspase 8 that may suppress the spread of neuroblastoma. This gene is missing in 70 percent of aggressive neuroblastomas.

Diagnostic imaging tests may be performed to locate primary tumors or possible metastasis. Location makes finding some primary tumors difficult. Imaging tests may be difficult to perform on infants because they must remain motionless for extended periods of time. Some imaging tests that may be used include:

• X-rays. A chest x-ray is taken to show if there are masses in the organs and bones in the chest cavity. If an x-ray locates a tumor, a CAT scan or MRI will be performed.
  
  
• CAT scan (computed axial tomography). A computerized x-ray that takes three-dimensional images of the body to locate tumors. The CAT scan is much more accurate than standard x-rays. The chest, abdomen and pelvis are scanned. Tumors in the brain, spinal column and other areas appear in the images.
  

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  MRI (magnetic resonance imaging). Magnetic and radio waves are used to create detailed images of internal organs to locate tumors.
  
  
• PET scan (positron emission tomography).  A radioactive tracer substance is injected into a patient’s bloodstream. Cancer cells attract the substance and create “hot spots” that appear on the image. PET scan is commonly used to detect cancer that has spread in the body.
  
  
• Bone scan. Radioactive material injected into the bloodstream collects in the bones and images are taken by scanner.  A bone scan can detect cancer cells in the bones, which is a common location for neuroblastoma to spread.
  

If tumors are located, the physician may order the following:

• Biopsy. Samples of tissues from the suspected tumor are obtained for analysis by a pathologist who determines the presence of cancer.
  
  
• Bone marrow biopsy. Samples of bone marrow (spongy tissue inside large bones where blood cells are produced) tissue can be taken to view cells under a microscope.