A movable subcutaneous bulging mass in the middle finger may be due to tendon sheath cyst, subcutaneous lipoma, tenosynovitis and other factors. 1. Tendon sheath cyst: the disease is caused by chronic injury to the joint, resulting in increased synovial fluid in the synovial cavity. A slow-growing cyst-like tissue may appear in the middle finger, which has no adhesion with the surrounding tissues and can be pushed when the cyst diameter is small. 2. Subcutaneous lipoma: when the middle finger suffers from subcutaneous lipoma, there will be a limited lump-like tissue under the skin, with clear boundaries with the surrounding tissues, which can be pushed in general. 3. Tenosynovitis: the disease is mainly due to aseptic inflammatory reaction caused by repetitive mechanical injuries. When the middle finger is sick with nodular tissue, there will be subcutaneous swellings, which can usually move with the joints. There are many factors that lead to the middle finger subcutaneous bulging lumps can move, it is recommended that the patient timely consultation to identify the cause of the disease after treatment.