Joint pains in your hand’s small joints or small, slow-growing swellings on your hands? Read about Digital Mucous Cysts
What are Digital Mucous Cysts?
A digital mucous cyst refers to a small benign cyst that is located towards the ends of the fingers or under the nail bed. These cysts involve the distal joints of the fingers and can sometimes involve the toes. Digital mucous cysts are a fairly common condition and form a part of a group of conditions called ganglia.
What causes Digital Mucous Cysts?
There does not appear to be a clear cause for digital mucous cysts. It is believed that they occur due to connective tissue degeneration along with osteoarthritis of the joints in the hand. Some tumors are also believed to cause this condition.
Symptoms and Diagnosis
Most patients are asymptomatic. When digital mucous cysts develop, they start off as small swellings that can grow gradually over a period of months. Patients also complain of joint pains in the small joints of the hand and this is usually related to osteoarthritis. In some cases, patients report a history of trauma to the joints.
On examination, the cysts appear as small round swellings at the nail bed or at the distal finger joints, called the distal interphalangeal joints. They often affect the middle finger of the dominant hand. They usually occur as a single lesion but sometimes there may be multiple cysts. Pain occurs if there is involvement of the nearby nerve fibers.
There are no specific diagnostic techniques as such and very often digital mucous cysts are diagnosed from history and clinical examination. X-rays of the hands may show fairly non-specific changes and ultrasound imaging can demonstrate a mass structure with well-defined walls. In some cases, CT scan or MRI may be performed.
Fine-needle aspiration of a digital mucous cyst demonstrates the presence of thick but clear gelatinous fluid within the cyst.
How are Digital Mucous Cysts treated?
Treatments include a variety of conservative methods such as heat application, massage therapy and hot soaks. Heparin cream and steroid cream can be used as well. In some cases, phenol is used to chemically cauterize the cyst.
If the condition is severe or does not respond to conservative treatment, surgical treatment of digital mucous cysts is offered. The simplest form of surgical treatment includes recurrent aspiration of the fluid from within the cyst using a wide bore needle. This is occasionally followed by injection of a steroid into the cyst. Commonly used steroids include hydrocortisone and triamcinolone.
Cryotherapy is another option. Sclerotherapy has also been used with the help of certain chemicals, but care must be taken to ensure that the chemicals used do not spill out into the neighboring tissues. Despite the availability of all these measures, most surgeons prefer to just excise the digital mucous cyst and depending on the size of the cyst offered a skin graft to the area.
Unfortunately, digital mucous cysts are prone to recurrence and therapy procedures may be required within a few months of treatment.