Neuroblastoma, a tumour of the sympathetic nerve tissue, is the most common solid tumour in children after brain tumour. It usually arises from the suprarenal gland deep in the abdomen. But it can also occur in the chest, the neck and the pelvic cavity. Fifty percent of the cases are found in children under the age of 2 years. This tumour grows rapidly and may already have spread beyond the site of origin when the child is first examined.
Children with neuroblastoma exhibit a variety of symptoms. They usually experience weight loss, poor appetite, fever and anaemia. Some children may also have diarrhoea, hypertension or profuse sweating. When the tumour occurs in the abdomen, a lump is often noticed. If the tumour occurs in the chest, the child coughs, has respiratory difficulties or even swelling of the face. The tumour usually spreads to the bone, especially the skull and limb bones. When the tumour spreads to the orbits, it will cause bruises and swelling around the eyes.
In addition to the usual blood tests, all day urine samples are collected for catecholamine measurement to support the diagnosis. A bone marrow biopsy is done to evaluate metastatic involvement. Ultrasound studies and a computerized tomography (CT) scan of the abdomen or the chest help to locate the site of the tumour and examine the involvement of the surrounding tissues. These tests are also used to assess the extent of tumour spread. Sometimes special tests such as isotope scans are helpful in confirming the diagnosis.
Surgical removal of the tumour is the most effective treatment. Unfortunately, the tumour is often very large or has spread to other organs when diagnosis is made. Anti-cancer drugs will then be given to shrink the tumour so that the operation is easier. After the operation, drug treatment will continue, sometimes together with radiotherapy. The treatment will last about twelve to eighteen months, but the length of treatment will depend on the stage of the disease. Children with a late stage tumour or bone erosion by tumour may need radiotherapy to control the disease and to reduce pain and suffering.
The chance of cure for neuroblastoma depends on the site and histological characteristics of the tumour, the patient's age and the degree of tumour spread at the time of diagnosis. For localized and well differentiated tumour in a child older than 2 years, the survival rate is over 80%, whereas, if the tumour is widespread, usually in infancy, the chance of survival is not good. Although there has been much advance in treatment in the past decade, the results in treating the poor prognostic group are still not satisfactory. New forms of treatment using bone marrow transplants are under study.