What are malignant tumors?

Related conditions:
Most cancers

Definition:

Malignant tumors are those that invade surrounding tissue. Commonly known as cancer, cells of malignant tumors are abnormal in morphology, tend to be larger than normal, and have odd shapes and large and irregular nuclei. By entering into the bloodstream or the lymphatic system, these cells spread to surrounding tissue, where they damage the tissues and organs. A sarcoma is a cancer of the connective tissue, and carcinomas are of epithelial origin. Malignant tumors are named using the Latin or Greek root of the organ of origin as a prefix and “sarcoma” or “carcinoma” as the suffix. For example, a malignant tumor of the liver is called hepatocarcinoma; a malignant tumor of the fat cells is called liposarcoma.

Risk factors: The most common risk factors for development of malignant tumors include tobacco use; exposure to ultraviolet (UV) radiation, ionizing radiation, certain chemicals, and viruses; and family history.

Etiology and the disease process: A mutated cell that continues to divide is a hallmark of cancer. The deoxyribonucleic acid (DNA) repair mechanisms are damaged, and the immune system is compromised such that the tumor cells rapidly multiply undeterred. Additionally, the tumor has an extensive vasculature that provides nutrients and oxygen for its growth.

Symptoms: Unusual bleeding or discharge, a change in the shape or coloration of a wart or mole, a sore throat that does not heal, unexplained weight loss, persistent cough, and anemia are some warning signs. Many symptoms are caused by the fatigue, pain, and stress imposed on the body by malignant tumors.

Screening and diagnosis: X rays, ultrasound, magnetic resonance imaging (MRI), and computed tomography (CT) scans are used to detect changes in tissues or organs, and blood tests are used to monitor abnormal cell counts. Presence of tumor markers such as prostate specific antigen (PSA), carcinoembryonic antigen (CEA), and human chorionic gonadotropin hormone in the blood are used to screen high-risk individuals.

Treatment and therapy: Malignant tumors can be removed before they metastasize (spread), but frequently they grow back. Besides a person’s age, general health, and response to treatment, the outcome depends on the type and location of the cancer, the stage of the disease (the extent to which the cancer has spread), or its grade (how abnormal the cancer cells look and how quickly the cancer is likely to grow and spread). Treatment includes surgery, radiation therapy, chemotherapy, hormone therapy, or biological therapy. However, most often a combination of therapies is required for complete eradication of the malignancy. Choice of a healthy, active, tobacco-free lifestyle with a minimum exposure to harmful UV rays can go a long way in preventing cancer.

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