The term malignant can be used in different ways, either to describe a cancerous tumor or a very serious medical condition. There are several similarities as well as differences between malignant and benign tumors. Learn about the characteristics and behavior of malignant tumors, the important ways in which they differ from benign tumors, and why it can sometimes be difficult to tell the difference between the two.
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Medical Definition of Malignant
In medicine, the word malignant is a term referring to a condition that is dangerous to health. While it is often used interchangeably with cancer, the term is also used to describe medical and psychological conditions other than cancer that are dangerous or ominous.
Synonyms of malignant in medicine include cancer, virulent, or malevolent. In contrast, antonyms (opposites) of malignant in medicine refer to processes that are not dangerous to health or well-being and include terms such as benign, noncancerous, or harmless. That said, some malignant conditions are very treatable, whereas some benign conditions may be life-threatening.
Malignant Tumors
A malignant tumor (cancerous tumor) is one that is invasive and can spread to other parts of the body.In contrast, tumors that stay localized and don’t spread are calledbenign. Benign tumors may grow quite large and can do damage, but they do not usually spread through the bloodstream or lymph vessels to other parts of the body.
Malignant Conditions
Not all malignant conditions are cancerous. For example, the phrasemalignant hypertensionis used to describe blood pressure that is dangerously high, but in this context, it has nothing to do with cancer.
Likewise, the condition malignant hyperthermia describes an emergency situation in which a dangerously high fever develops during surgery with general anesthesia.Malignant otitis externais a complication of swimmer’s ear that was very serious (and sometimes still is) before the advent of antibiotics.
Malignant Mental Health Conditions
The term malignant may also be used when describing mental health conditions, such as a side effect of psychiatric drugs referred to asneuroleptic malignant syndromeor the description of a particularly damaging form of narcissism called malignant narcissism.
Characteristics of Malignant Tumors
Similarities to Benign Tumors
Some ways in which benign and malignant tumors are similar include:
How Malignant Tumors Differ from Benign Tumors
Some of the ways that malignant (cancerous) tumors differ from benign tumors include:
Cancer Cells vs. Normal Cells: How Are They Different?
Difficulty Distinguishing Between Benign and Malignant Tumors
If your healthcare provider isn’t certain whether a tumor is benign or malignant you may be surprised. Isn’t that obvious? On scans such as a CT scan, MRI, or even PET scan, benign and malignant tumors can sometimes look very similar. Yet it can sometimes be difficult to tell the difference even under the microscope. While there are many differences between cancer cells,precancerous cells, and normal cells there is also a lot of overlap. In addition, in many tumors, there is a mixture of normal, precancerous, and cancer cells. Even among cancer cells, there can be differences in the appearance of these cells in different parts of a tumor (something referred to as “heterogenicity”).
Pronunciation:mu-leeg-nant
Examples:Rodney was saddened to learn his tumor was malignant and he would have to go through treatment for cancer.
A Word From Verywell
Though in general, malignant tumors are more serious and life-threatening than benign tumors, this is not always the case. Advances in the treatment of some cancers have greatly improved survival rates, and some malignancies are highly survivable. At the same time, some benign tumors (such as some benign brain tumors or benign heart tumors) can lead to serious disabilities or even death.
6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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