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Biology and You

You and Your Cells

What is a malignant cell?

Cells that reproduce quickly and expand beyond the tissue or organ where they originated are described as malignant or cancerous. Malignant tumors are more difficult to eradicate because they may grow in organs far removed from their origin. For example, cancers that originate in the lung can quickly spread (or metastasize) to the brain and other organs through the circulatory system.