Malignancy
（重定向自Malignant disease）
Malignancy (fromLatin male, meaning "badly",and -gnus, meaning "born") is the tendency of a medical condition to become progressively worse.
Malignancy is most familiar as a characterization of cancer. A malignant tumor contrasts with a non-cancerous benign tumor in that a malignancy is not self-limited in its growth, is capable of invading into adjacent tissues, and may be capable of spreading to distant tissues. A benign tumor has none of those properties.