Neuroblastoma

General characteristics

Neuroblastomas are the most common abdominal tumors of early childhood.

Location

In up to 50% of cases neuroblastomas are located intra-abdominally, and two thirds of all cases originate from the adrenal medulla. They can however originate from every ganglion of the sympathetic chain.

Localized also in the head and neck area (2–5%), in the thorax (10–20%) or in the pelvis (5%). At the time of diagnosis 50–75% of the children already have metastatic disease with metastases to the bone marrow, the skeleton, the liver, the skin and in later stages of this disease to the lungs. Neuroblastomas are often characterized by a polycyclic border and demonstrate growth over the midline.

Morphology

They can infiltrate the kidneys and encase the large vessel; in up to 50% of all cases they infiltrate the spinal canal. As the disease almost exclusively occurs in children, staging exams without ionizing radiation are desirable. Therefore, initial reports on whole-body MRI for the local staging and the detection of distant metastasis in patients with neuroblastoma have been published.

The SI of neuroblastoma on T1-weighted images is almost identical to that of the renal medulla. Compared to the renal cortex the tumors often appear to be slightly hypointense. On T2-weighted images, neuroblastomas have an isointense SI compared to a normal kidney. In up to 84% of all cases, calcifications are present in neuroblastomas and account for an inhomogeneous SI distribution. Post-chemotherapy neuroblastomas also reveal inhomogeneous SI.

Treatment

The assessment of the relation of the tumor to the large vessels and to the spinal canal is of crucial importance for the planning of an operation. For this purpose, coronal images and transfers images are most suitable. Identification of the potential organ of origin of neuroblastomas can most easily be done on coronal slices.