Glossary of Key Terms

Pleuropulmonary Blastoma DICER1 Syndrome Study

Tumor

An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancer), or malignant (cancer). Also called neoplasm.

Gene

The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a specific protein.

Syndrome

A set of symptoms or conditions that occur together and suggest the presence of a certain disease or an increased chance of developing the disease.

Mutations

Any change in the DNA sequence of a cell. Mutations may be caused by mistakes during cell division, or they may be caused by exposure to DNA-damaging agents in the environment. Mutations can be harmful, beneficial, or have no effect. If they occur in cells that make eggs or sperm, they can be inherited; if mutations occur in other types of cells, they are not inherited. Certain mutations may lead to cancer or other diseases.

Multinodular goiter

Goiter is a term used to describe any enlargement of the thyroid gland, which can be caused by iodine deficiency or a thyroid disorder. A multinodular goiter contains multiple distinct nodules within the goiter, but its cause is less clear. Sometimes this condition can be caused by certain genetic factors.