NCI Dictionary of Cancer Terms

The NCI Dictionary of Cancer Terms features 8,351 terms related to cancer and medicine.

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(VAYR-ee-uh-bul ek-SPREH-shun)
Refers to the difference in the way that signs and symptoms of a genetic condition can show up in individual patients who have that condition. For example, some patients with neurofibromatosis type 1 may have only mild symptoms, such as brown spots and freckling on the skin, and others may have more severe symptoms, such as brain tumors and tumors on the nerves.