—An abnormal chromosome found in 20% of adults and 5% of children with ALL, the presence of which indicates a somewhat worse prognosis.
—Areas within the body which are relatively impermeable to medications such as chemotherapy but which can harbor cancerous cells. Some of these sites are the central nervous system, the testicles, and the eyes.
—A gland within the chest involved in the maturation of immune cells that can be invaded by T lymphocytes in T-cell ALL.
Marianne Vahey M.D., The Gale Group Inc., Gale, Detroit,