Final answer:
An abnormal mass of tissue due to neoplasia is called a tumor, which can be benign or malignant. Malignant tumors, or cancers, have the ability to invade other tissues and metastasize to other regions of the body.
Step-by-step explanation:
An abnormal mass of tissue as a result of neoplasia is known as a tumor. Neoplasms can be either benign (non-cancerous) or malignant (cancerous), with the latter being characterized by uncontrolled cell growth, the potential to invade adjacent tissues or even spread to different parts of the body through a process called metastasis. While not all mutations lead to the formation of tumors, those that affect crucial cell proliferation proteins can result in a disorganized cellular growth, creating a tumor with an abnormal structure. Malignant tumors, in particular, are harmful because they breach the confines of their original tissue, enabling further cell mutation and metastasis.