In English | En español
Questions About Cancer? 1-800-4-CANCER

NCI Dictionary of Cancer Terms

Page Options

  • Print This Page

Widget

NCI Dictionary of Cancer Terms



thymus  listen  (THY-mus)

  An organ that is part of the lymphatic system, in which T lymphocytes grow and multiply. The thymus is in the chest behind the breastbone.

Enlarge
Anatomy of the thymus gland; drawing shows the thymus gland in the upper chest under the breastbone. Also shown are the ribs, lungs, and heart.