CYST IN THE WRIST

Ganglion cysts are small swellings that occur most commonly around the wrist joint. "Though they are called tumors medically, they hardly behave as one. Technically speaking they are benign (harmless) or simply non-cancerous. But often they are a source of distress to many," says Dr Biswajit Dutta Baruah, consultant orthopaedic surgeon, KIMS Oman hospital.

Pain in the wrist can often be caused by benign cysts. Most commonly, ganglion cysts are 12 cm in diameter and appear as knobbly or rubbery swellings on the back of the wrist. At times these cysts occur on the palmar side of the wrist as well. Many a times, they can be firm to hard, and patients often insist to their doctors, mistakenly that they have bony swellings on the wrist. In addition to it being unsightly, many patients complain of pain associated with the swelling.

Pain is during activities involving the wrist like typing or writing, or lifting weights. For a few the pain may radiate or pass along the forearm towards the elbow or along the hand to the fingers. Some feel loss of sensation or decreased strength in hand grip. More than distressing, the pain is characteristically annoying in nature and interferes with their daily activities.

Cyst near joints

It is not exactly known to date as to why these swellings occur. Many reasons have been put forth but none have been accepted uniformly. At the gross level, the cyst is a sac filled with fluid, almost like a balloon. At the tissue level there is some resemblance of the wall of the cyst to the lining of the joint or covering of the tendon - structure that connects the muscle to the bone. Often the sac is connected by a tube-like stalk to the underlying joint or tendon. This has led many to propose that the cyst is a projection (herniation) of the joint lining tissue (synovium or tenosynovium) to the area outside the joint. The cyst is filled with fluid that is thick and oily (viscous) in nature resembling the fluid present in our joint or that surrounding the tendons. Some have proposed that there is a one-way valve mechanism in the stalk of the cyst permitting the fluid to move from the joint into the cyst, but not the other way around. And with the passage of time, the fluid thickens to a jelly-like consistency. There are others who believe that the degeneration of tissues around the joint (peri-articular) structures leads to the formation of a ganglion. Most studies that looked into the tissue level structure of a ganglion cyst have failed to find any signs of inflammation thus debunking inflammation as a cause. Some suggest that opening in the joint capsule - tissue that surrounds the wall may lead to leak of joint fluid and its eventual build-up and cyst formation.

Tackling the cyst

As one study elegantly put it, the treatment of ganglion cysts has weighed on the consciousness of medicine for some time. During early days treatments such as rubbing early morning saliva on the swelling, binding a plate of lead onto the wrist, applying repeated pressure by the thumb or hitting the cyst with a book were resorted to. All these methods have been long abandoned by the medical community. Ganglions are notorious for recurrence whatever the treatment undertaken. Placing a needle inside the cyst and removing the contents by the suction effect of a syringe - a procedure called aspiration is undertaken by many for it is simple and can be done at the out-patient clinic. Thick jelly-like consistency may make this difficult. Recurrence rates are very high after aspiration, so some repeat the process 2-3 times before final resolution of the cyst. Few have recommended injecting steroid (cortisone) into the sac following removal of the cyst contents. Since inflammation has never been established, this has not shown to be beneficial compared to plain aspiration. Others may splint the wrist in the belief that movement of the wrist may have a pumping effect and reformation of the cyst. But studies have shown no such benefit and splinting is often unnecessary. A few surgeons have passed a thread through the ganglion in an attempt to milk the fluid out, and tie it over gauze (thread method). Though simple, concern remains over infection and as such this has not been accepted widely in the medical community.

Surgical excision

Surgical excision of the ganglion cyst remains the gold standard. In the early days recurrence was as high as 40-50%. However with the evolution of techniques and complete removal of the cyst, its wall & pedicle, and a cuff of adjoining tissue recurrence rates have dropped down to 5-7%. Scarring and damage to the adjoining structures is possible and therefore, surgery is resorted to when the cyst is large, increasing in size or interfering with daily activities. Cosmesis is not a valid reason as it will eventually be replaced by a scar.

Most studies reveal that a significant number of ganglia will spontaneously resolve in a few years. Further the fact that they are benign and harmless should suffice to alleviate a patient’s fear. Understanding that for the patient what the ganglion represents is more important than what the ganglion actually is should help the doctor convince him or her that treating the patient without resorting to surgery is possible.