Masses in the hand or upper extremity, many times will be a ganglion cyst, which is basically a ball of joint fluid. Sometimes the masses may be composed of other tissue, and these are classified as benign or malignant. Most masses in the hand and upper extremity are benign, and very rarely,a mass may be malignant (cancerous). Your surgeon will evaluate you and let you know about the most likely diagnosis. There are variety of different treatment options for these masses some of which can be treated by minimally invasive methods.