What is the cause of a non cancerous tumor on the left side of right wrist on the tendon?

A non-cancerous tumor on the left side of the right wrist, particularly on a tendon, is often a ganglion cyst or a lipoma. Ganglion cysts typically arise from the synovial fluid in joints or tendons, while lipomas are benign fatty tumors. These growths can be caused by repetitive motion, injury, or genetic predisposition. While usually harmless, they can sometimes cause discomfort or restrict movement.