A malignant tumor is defined as

A malignant tumor is defined as

• A. A non-cancerous tumor that never grows
• B. A cancerous tumor that metastasizes to one or more organs
• C. A benign tumor that becomes malignant
• D. A tumor caused by infection

Answer: (B)

A malignant tumor is a cancerous growth that invades surrounding tissues and has the ability to spread to distant sites (metastasize) to other organs. This invasive, metastatic behavior distinguishes malignant tumors from benign ones, which stay localized and do not invade or spread. So the best description is a cancerous tumor that can metastasize. The idea that a benign tumor becomes malignant isn’t the defining feature, and tumors caused by infection don’t define malignancy even though infections can be related to cancer risk in some cases.

A malignant tumor is a cancerous growth that invades surrounding tissues and has the ability to spread to distant sites (metastasize) to other organs. This invasive, metastatic behavior distinguishes malignant tumors from benign ones, which stay localized and do not invade or spread. So the best description is a cancerous tumor that can metastasize. The idea that a benign tumor becomes malignant isn’t the defining feature, and tumors caused by infection don’t define malignancy even though infections can be related to cancer risk in some cases.