Benign tumors

ALSO KNOWN AS: Mass, benign neoplasm, noncancerous tumor

RELATED CONDITIONS: Lipoma, chondroma, adenoma, hemangioma

DEFINITION: A benign tumor is a noncancerous growth that does not invade nearby tissue or spread to other parts of the body. Benign tumors are caused by cell overgrowth and are thus distinct from other tissue formations, such as cysts or abscesses. A tumor is a mass of tissue that serves no useful purpose and exists at the expense of healthy tissues. Benign tumors do not exhibit any of the three characteristics of malignant tumors: Benign tumors do not invade nearby tissues, do not metastasize, and do not grow in an unlimited, accelerated manner.

Risk factors: The specific risk factors for benign tumors vary depending on the location of the tumor and the tissue type. For example, risk factors for benign breast tumors include such factors as body mass index, height, and breast size. Problems with the body’s immune system can cause both malignant and benign tumors. Certain viruses can also play a role in tumor formation, as in cervical cancer and hepatocellular carcinoma. Exposure to loud sounds or music can increase the risk of developing benign tumors in the ears, as can repeated exposure to cold water. Smoking can cause benign tumors to appear in the lower lip.

Etiology and the disease process: The source of most benign tumors is a discrete population of cells that have been altered through acquired genetic defects. Such abnormal tissue masses are termed benign neoplasms. Benign tumors are usually encapsulated, meaning that they are confined to a specific, localized area and surrounded by a thin layer of tissue. This limits the growth rate and invasive potential of the tumor. In the liver, the most common benign tumors are hemangiomas. These tumors are made of abnormal blood vessels, most likely present at birth but only detected later when they cause symptoms or are identified on an ultrasound or computed tomography (CT) image obtained for another reason. Hemangiomas occur more frequently in women. Infections can cause benign tumors to appear in the larynx, which can be detected by symptoms of hoarseness.

Incidence: Benign tumors are common and usually not life-threatening. However, benign tumors can still lead to death, although far fewer deaths occur than with malignant tumors. Benign tumors can cause serious injury or death by pressing on vital organs (such as the brain), tissues, or nerves in the vicinity of the growth. Benign tumors in the kidneys can range in size from 1 millimeter to several centimeters without causing any symptoms or requiring treatment. Benign tumors in the lungs are relatively rare, making up only 8 percent of all tumors in the lungs. Benign tumors in the stomach account for 5 to 10 percent of all stomach tumors, afflicting many people between the ages of forty and fifty. Men are more likely to develop benign stomach tumors compared with women.

Symptoms: Benign tumors may be asymptomatic or may cause one or more of the following symptoms depending on their location and their specific tissue type: itching, obstruction of the intestines, bleeding or occult blood loss resulting in anemia, cosmetic changes, hormonal syndromes caused by hormones secreted by the tumor, compression of the blood vessels or vital organs, and pain or dysfunction induced by pressure. Benign tumors in the nose have the following symptoms: difficulty breathing, bleeding, headache, or severe eye pain and blurring.

Screening and diagnosis: When a tumor is found, a biopsy is performed to determine whether the tumor is benign or malignant. Although usually not life-threatening, once diagnosed, benign tumors should be monitored regularly, as a benign tumor may progress and become a malignant tumor. For instance, a colon polyp is a type of benign tumor, but most incidences of colon cancer develop from colon polyps. The most common benign tumors of the ear occur behind the ear. They can also occur within the ear canal or on the scalp and can be discovered during a routine ear examination, which includes audiometry (hearing tests) and tympanometry (middle ear testing). When looking into the ear, the doctor may observe cysts or benign tumors within the ear canal.

Treatment and therapy: Often, a benign tumor will require no treatment if it is located in a low-risk area where it will not cause symptoms or disturb the proper function of an organ. If causing symptoms, benign tumors are usually treated by surgery. Benign tumors may also be removed for cosmetic reasons. The incidence of recurrence after surgery is typically low. Chemotherapy and radiation therapy are usually ineffective in the treatment of benign tumors. Benign tumors of the brain may be surgically removed to prevent harmful effects on the surrounding normal brain tissue. In the 2020s, new treatments for benign tumors were developed. Radiofrequency ablation and high-intensity focused ultrasound presented patients with a less invasive treatment method for shrinking and removing tumors. New oral and intravenous medications also helped destroy benign tumors. 

Prognosis, prevention, and outcomes: Benign tumors tend to grow more slowly than malignant tumors and are far less likely to threaten health. If a tumor is benign, the prognosis is generally very good. The situation can be more serious if the tumor is located in the brain.

Bibliography

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