Similiar to a Ganglion, it contains thick fluids. It is typically located  over the palmar aspect of the hand, very close to the Metacarpo Phalangeal Joint (MCPJ), near the base of the finger. The nodule is not harmful but can  cause pain, especially when gripping. Retinacular cysts can interfere with function. Although approximately  50% of cases do resolve spontaneously, sometimes a patient can’t afford or he is simply unwilling to wait for spontaneous resolution, which will take several months to occurr.

 

What Causes it?

This is not always clear. Hand injury can predispose to it. Osteoarthritisin the fingers may also increase the risk of developing flexor tendon sheath cysts. 

 

Diagnosis.

It is essentially clinical. The doctor will ask basic questions,  such as:

How long the cyst has been present;

Whether its size has changed;

Whether it is painful and when etc

 

Physical Examination

Palpation will allow assessment of  mobility, size and intensity of pain. Shining a light on the cyst (Transillumination) can save you an ultrasound scan, speeding up management.

Occasionally,  x-rays, an ultrasound or an MRI scan, may be necessary to clarify the diagnosis.