Glossary

Killer T Cells

antigen-stimulated T lymphocytes or cytotoxic T cells that attack foreign antigens directly and destroy cells that bear those antigens.

neuroblastoma

Neuroblastoma is a malignant (cancerous) tumor that develops from nerve tissue. It occurs in infants and children. Causes, incidence, and risk factors

Neuroblastoma can occur in many areas of the body. It develops from the tissues that form the sympathetic nervous system (the part of the nervous system that controls body functions, such as heart rate and blood pressure, digestion, and levels of certain hormones).

Most neuroblastomas begin in the abdomen in the adrenal gland or next to the spinal cord, or in the chest. They may also start in other areas. Neuroblastomas can spread to the bones (face, skull, pelvis, shoulders, arms, and legs), bone marrow, liver, lymph nodes, skin, and around the eyes (orbits).

The cause of the tumor is unknown. Neuroblastoma is most commonly diagnosed in children before age 5. The disorder occurs in approximately 1 out of 100,000 children and is slightly more common in boys.

Neutropenia

Neutropenia is an abnormally low level of neutrophils in the blood. Neutrophils are white blood cells (WBCs) produced in the bone marrow that ingest bacteria. Neutropenia is sometimes called agranulocytosis or granulocytopenia because neutrophils make up about 60% of WBCs and have granules inside their cell walls. Neutropenia is a serious disorder because it makes the body vulnerable to bacterial and fungal infections.