A ganglion cyst is a soft tissue mass that is commonly found in the hand and wrist as well as the foot and ankle. The cause of the cyst is not know but has been associated with minor preceding trauma to the region. The cyst is commonly found close to joint structures or tendons and often communicates with these structures. The cyst is filled with a clear to yellow gelatinous fluid which is thought to be the same synovial fluid that is the lubricant in our joints and tendons.
The identification of any soft tissue mass on the body can be very alarming. This non-tumor can cause sharp radiating pain if it is in close proximity to a nerve or can cause deep achy quality pain if is is close proximity to muscle or soft tissue of the foot. The size can vary based on its location on the foot and ankle. The mass usually will not cause any swelling or discoloration to the area and can often times be moved if manipulated by hand.
Imaging of the cyst is usually not needed but can be performed depending on the clinical situation. Regular x-rays are not helpful as they show only bone tissue. Ultrasound is an inexpensive diagnostic imaging that can provide supportive information about the diagnosis. MRI which identifies soft tissue problems is probably the strongest way to image the cyst dimensions.
The best way to diagnoses the cyst is by performing an aspiration. Aspiration is the attempted removal of the cyst fluid material with a needle and syringe after the area has been anesthetized. Aspiration of the cyst with the administration of cortisone is a common treatment approach. This has been shown to help resolve the cyst but it is not known whether the cyst decreases in size or actually resolves. Once the definitive diagnosis is made with aspiration it is not necessary to treat the cyst unless pain is present. Surgical excision of the cyst is the most definitive treatment if needed based on symptoms. The surgical care is performed in an outpatient surgical setting and is typically performed with light sedation.