Tumor tissue is necessary to assign a risk group and give appropriate therapy.
Surgery is important to establish the diagnosis and obtain sufficient tissue for pathology and molecular studies.
Biopsy may be obtained using a laparoscope or at limited laparotomy with incisional biopsy.
For patients older than 18 months with stage 4 disease, bone marrow biopsy can obtain sufficient tumor tissue for diagnosis together with elevated urinary catecholamines. Testing for MYCN amplification and 1p/11q loss of heterozygosity may be successfully performed on bone marrow if there is at least 30-40% bone marrow involvement.
Only very rarely is it possible to resect a neuroblastoma completely at diagnosis.
If tumor appears localized, every effort should be made to resect as much of the tumor as possible. At the operation, as well as removal of the primary, extent of disease should be assessed. Local lymph nodes should be biopsied and neural foramina inspected when relevant.
The International Neuroblastoma Pathology Classification (INPC) System is used to determine the prognosis along with other factors such as age and MYCN amplification.