Review of Treatments of Mucous Cysts in the Hand
Mucous cysts are abnormal sac-like bumps filled with fluid. They are benign (noncancerous), but they may become annoying to the patient because of how they look or they may cause pain. Currently, treatment of these mucous cysts may be surgical or nonsurgical. Removing the cyst surgically may not always relieve the pain if there is any arthritis in the joint just below the cyst. In this case, the suggested treatment is usually joint arthrodesis, or fusion of the joint. If this isn't done, a new cyst will likely form.

Injecting steroids is a nonsurgical way of treating a mucous cyst. One researcher, Epstein, followed six patients for between one to nine months following a steroid injection into the cysts. All six recurred. Another researcher, Goldman, followed 41 patients after injecting their cysts with corticosteroids and he found that 68 percent recurred. In yet another study, 80 patients were followed for a minimum of two years after having multiple punctures to their cysts and steroid injection. There was a 40 percent recurrence. Eight patients had repeat injections and five had recurrence again. Two of the 80 patients developed infections that were treated with oral antibiotics.

Surgical procedures include excising or removing the cyst, or draining it. A skin graft could be needed to cover the area, but is not always necessary. If there are osteocyte formations (small bits of bone), surgical treatment may include debriding (removing dead tissue) in the joint. In one study of 25 patients who underwent excision, led by Crawford, seven patients had recurrence of the cyst. Another researcher, Dodge, followed 18 patients for about 7.5 years after excision of not only the cysts but any osteophytes that were obviously present. He found that five patients had recurrence.

More involved surgery, in which the surgeon deliberately goes into the knuckle to remove osteophyte formations, may be necessary in some cases. A study of 54 patients followed for a minimum of two years, by Rizzo, found that there were no recurrences and in 25 of 31 fingers that had nail ridging, the ridging went away. There were no reports of joint instability or deformities, but three patients did develop infection. Two were treated with oral antibiotics but one needed surgery to clean out the joint. Eighty-six patients who had cysts excised along with osteophytes were followed by researcher Fritz. He applied rotation flaps on 58 of the 86 fingers. After about 2.6 years, three of the 86 patients had recurrence. Fifteen patients had limited range of motion and extension. One patient developed an infection, two developed septic arthritis, which required arthrodesis. Fifteen of the 25 patients who had nail deformities saw them resolve, but four patients who did not have a nail deformity before surgery developed one after.

In another study, by Kasdan, 113 cysts were removed along with osteophyte debridement. Two patients had cysts return and two developed infections. Forty of the 46 nails with deformities were corrected.

There are times when the joint needs to be debrided but there the cyst will not be removed. A study of 20 cysts, by Gingrass, looked at the cysts that were left intact after the osteophytes were debrided. There were no recurrences during the three-year follow-up. Eighteen fingernails were no longer deformed and two had only slight deformations after surgery.

When a patient with thinned skin has mucous cyst on the finger, treatment is controversial. Some surgeons feel that the cyst and skin should be removed and replaced with a graft. However, research is showing that thin skin can heal, so this may not be necessary.

The author of this article presents a 62-year-old woman who complained about a bump that appeared nine months earlier, which was just below her cuticle, on the finger. It caused a groove in her nail, as well. X-rays showed that the patient had mild osteoarthritis, with some osteocyte formation but she had good range of motion in the joint. In this case, the author did not suggest surgery, saving this in case nonsurgical treatment failed. He recommends aspirating the cyst, asking the patient to return if the cyst occurs. The reasoning allows the patient to consider the ramifications of surgery. He also does not suggest using steroids due to the recurrence rate.

If the patient were to return with a recurrence of the cyst, then surgery would be recommended, although pain relief can't be guaranteed.
Jeffrey E. Budoff, MD. Mucous Cysts. In The Journal of Hand Surgery. May 2010. Vol. 35. No. 5. Pp. 828-830.