What is a digital mucous cyst?
A digital mucous cyst is a small, benign growth at the end joint of a finger or under the nail bed. The cyst is rarely painful unless it impacts nearby nerve fibers. A digital mucous cyst most commonly affects the index finger of the dominant hand and usually occurs as a single lesion. Cysts may appear suddenly or develop over a period of months.
What causes this condition?
Although the exact cause is unknown, digital mucous cysts may be linked to connective tissue degeneration that occurs as the result of osteoarthritis. In rare cases, tumors or trauma may cause the lesions.
What are the symptoms?
Most digital mucous cysts are asymptomatic. They appear as a visible bump on the last joint of the finger or a groove in the fingernail. Sometimes, the cyst becomes painful or tender or irritation develops in the skin over the cyst.
How is a digital mucous cyst diagnosed?
In addition to a patient history and examination, your doctor may order and X-ray to assess the condition of your finger joint and look for underlying arthritis or bone spurs.
What is the treatment?
Most digital mucous cysts are asymptomatic and do not require treatment. Many cysts disappear spontaneously. If the cyst is painful, conservative therapies such as heat or steroid cream may help relieve symptoms.
If these measures fail to bring relief, surgery to remove the cyst may be necessary. In this outpatient procedure, the surgeon makes a small incision over the cyst, excises it, examines the joint and removes any bone spurs that may have formed. Patients wear a bandage for a few days, gradually add range of motion and resume normal activities within several weeks.