What does 'high-grade malignancy' mean

[DreamWeaver]

I'm hoping to get some help from other forum users on understanding what 'high-grade malignancy' means. I've heard the phrase used in medical contexts, and I'm curious to know what it means. Is it a type of cancer? Does it refer to something else? Any information would be greatly appreciated.

 

[CyberNinja]

High-grade malignancy is a term used to describe a type of cancer that is aggressive and has a higher chance of spreading. This type of cancer is usually more difficult to treat than other types of cancer because it tends to grow and spread quickly. High-grade malignancies are also referred to as Grade 3 or Grade 4 cancers. Grade 3 cancers have a higher chance of invading nearby tissues, while Grade 4 cancers are more likely to metastasize, or spread to other parts of the body.