digital mucous cyst
Thursday 25 July 2013
digital mucous cysts; mucoid cysts, synovial cysts, myxoid cysts, myxomatous cutaneous cysts.
Definition: Digital mucous cysts are nodules of the distal interphalangeal joint (DIP) of the hand or of the toes.
In 60-80% of cases, mucous cysts are associated with degenerative joint disease of the DIP joint. Studies have shown a pedicle between the cyst and the DIP joint capsule
The mechanism of formation of digital mucous cysts is unknown. Currently, it is believed that the cysts arise from mucoid degeneration of connective tissue and that this process, in most cases, involves communication with the adjacent DIP joint and possible coexistence of osteoarthritis.
Clinical and radiographic evidence of osteoarthritis is common at the site of the cysts, and the frequent presence of osteophytes and spurring of the DIP joint were recognized in the 1970s.
Active connection to the joint space may or may not exist, as the mucoblasts associated with the cyst appear capable of sustaining the process.