Final answer:
An abnormal mass of tissue is indeed a tumor, which can be either benign, causing little to no harm, or malignant, which is invasive and potentially life-threatening (cancer).
Step-by-step explanation:
True, an abnormal mass of tissue is called a tumor. Tumors can be the result of an abnormal proliferation of cells and can be classified as either benign or malignant. A benign tumor remains localized, does not spread to other tissues, and typically does not harm overall health, although it may be removed for comfort or to prevent potential cancerous growth. A malignant tumor, or cancer, is characterized by the ability to invade neighboring tissues and possibly spread to distant sites, a process known as metastasis. Neoplasms refer generally to newly formed, abnormal tissue growth, which can form tumors, such as in the case of leukemia, where a solid mass is not always present.