There are many types of benign tumors that vary in their placement in the body as well as in how harmful they can be. Benign tumors are not considered as dangerous as malignant tumors, because they do not spread as invasively as malignant tumors. They can, however, grow to sizes that can lead to organ failure if not treated. The main types of benign tumors include lipomas, leiomyomas, neuromas, hemangiomas and nodular tenosynovitis.
Lipomas occur in fatty tissue and are very common. They are usually easily discovered as lumps beneath the skin and treatment usually is not necessary. If a lipoma becomes overly large or painful, it can normally be removed by excision. This is usually done with a local anesthetic on an outpatient basis.
Leiomyomas are benign tumors of the internal organs that develop on the walls of blood vessels. They are commonly found in the uterus and are referred to as uterine fibroids. They are not usually life threatening, though they are often removed because they can interfere with the function of the organ to which they are attached. A similar tumor that develops in muscle tissue is termed rhabdomyoma, and is less common than leiomyomas.
Another class of benign tumors, and one that affects the nervous system, is the neuroma. Neuromas affect nerve tissue and can be brought on by trauma or other factors. The most common types of neuromas affect the foot — where they can produce painful swelling in the joints or between the toes — and the ear, where it is referred to as an acoustic neuroma.
Hemangiomas are the most common type of benign tumors that affect the blood vessels. They cause a buildup of blood vessels that is often visible on the top of the skin. This buildup is often referred to as a strawberry and it often will dissipate on its own. More severe cases can be treated with a laser that removes the buildup and reduces the discoloration on the skin. A hemangioma occasionally will occur around the eye or eyelid and may cause a reduction in vision that could require the tumor's removal by surgery.
Nodular tenosynovitis occurs in the joints, normally in the synovial fluid. It also is referred to as giant-cell tumor of the tendon sheath. It is a class of benign tumors that is most often found in the joints of the hand, including the wrist and fingers. While these tumors are usually painless, they can affect the mobility of the joint and are often removed by excision.