Synovial Cyst of the extensor digitorum superficialis: A case report.

BACKGROUND

A synovial cyst is a herniation of synovial tissue through a joint capsule, often mistaken for a ganglion cyst. The key distinctions are that synovial cysts have a synovial cell lining, while a ganglion cyst is delineated by dense fibrous connective tissue. Typically found near joints, synovial cysts are associated with conditions like osteoarthritis, prevalent in females aged 20 to 50. We present a rare case of a synovial cyst in the extensor digitorum superficialis of the right hand.

CASE SUMMARY

A 53-year-old Hispanic female visited our hand clinic due to a 3-year history of pain on the back of her right hand. At exploration, a 3 × 3 cm soft tumor was identified. Surgery revealed a clear-yellowish mass within the extensor digitorum superficialis tendon. Following the surgery, synovial cyst was confirmed by pathology and the patient was discharged without complications.

CONCLUSION

This case highlights the rare presentation of an intratendinous synovial cyst and emphasizes the importance of a comprehensive understanding of synovial cysts in the differential diagnosis of hand tumors.