The difference between tenosynovial giant cell tumor and tenosynovial cyst mainly includes different pathologic types, different imaging manifestations, and different treatment modalities. 1. Different pathologic types: tenosynovial giant cell tumor is a benign tumor, which occurs as a firm and painless mass in the fingers and hand, and may invade the adjacent bone; tenosynovial cyst is a cystic mass in the tendon sheath, which is filled with colorless and transparent fluid. 2. Imaging performance is different: tenosynovial giant cell tumor ultrasound performance for solid hypoechoic or uneven echo, clear boundary, dynamic observation, the swelling does not move with the tendon movement, the swelling is often seen within the rich blood flow signal; tenosynovial cysts in the ultrasound performance for the internal swelling was echogenic, the boundary is clear, most of them are ellipsoid or irregular shape, good internal translucency, no blood flow. 3. Different treatment modes: tenosynovial giant cell tumor usually adopts surgical resection; while a few tenosynovial cysts rupture on their own, and will not recur after the disappearance of the cyst, or the cystic fluid is absorbed and disappears after extrusion, but it is easy to recur. Surgery has the best efficacy and less chance of recurrence. After surgical resection, the specimen should be sent to pathology for clear diagnosis.