Intratendinous Ganglion Cyst of the Semitendinosus Tendon: First Reported Case and Literature Review

INTRODUCTION: Ganglion cysts are commonly seen in wrist joints and knee joint, but intra-tendinous ganglion cysts are extremely rare. We report the first case of intratendinous ganglion cyst of semi-tendinous tendon. CASE REPORT: A 4-year-old boy presented with painless soft tissue swelling over knee with no history of recent trauma. Radiograph was normal and USG showed a well-defined hypoechoic cystic lesion. Patient was taken for surgery and the lesion was removed. Lesion came out to be a ganglion cyst originating from the semitendinosus tendon. Post-operative USG was done to confirm complete removal of the ganglion. CONCLUSION: Intra-articular ganglion cysts are common, and we find it regularly in our daily practice. However, we should be aware of the occurrence of intratendinous ganglion cysts also which on examination may look like a lipoma. Thus for all cysts around the tendons, an USG is must. Also repeat USG should be done to rule out incomplete excision and recurrence.