Tumor (Neoplasm): Types, Symptoms & Treatment A tumor, also known as a neoplasm, refers to an abnormal growth of tissue that forms when cells divide and grow in an uncontrolled way. Tumors can develop in nearly any part of the body, and they vary greatly in terms of their size, shape, and potential impact on health. Understanding the types, symptoms, and treatments associated with tumors is crucial for early detection and effective...