The term malignant is often used to refer to the tendency of a medical condition, especially tumours (e.g. a cholangiocarcinoma), to become progressively worse over time, such as may result in eventual death.
There are two more specific uses of the term malignant:
- As may be applied to various disorders:
The term malignant may be used to describe and refer to any medical disorder that becomes life-threatening if left untreated, e.g. malignant hyper-tension.
- As used to describe certain tumours:
A malignant tumour is one that invades and destroys the tissue in which it originates (e.g. tissues of the bile duct(s) in the case of a cholangiocarcinoma), and which can spread to other tissues in different parts of the body via the blood and lymphatic systems. If left untreated malignant tumours may leading to progressively deteriorating health, leading to death.
The word "cancer" is also used to refer to the presence of malignant tumour(s).
Compare and Contrast: The opposite of malignant is benign. That is, a tumour that is not cancerous is benign.