Dr. Marc Blatstein comments that a ganglion to touch is a firm, rubbery mass that can occur on the top of the foot (as well as on other parts of the body), and they can enlarge and/or shrink in size. They generally occur without any apparent cause, but as a result of repetitive micro trauma. They can also arise spontaneously from a weakness in the soft tissue covering of a joint or tendon sheath, extending into adjacent joints. They become noticed as they enlarge often becoming painful. At times they may appear to resolve over time only to appear then to regrow back even larger.
Physical exam will reveal a firm, rubbery mass that can be moved side to side manually appearing to have discrete boundaries. Marc Blatstein states that an MRI is not necessary to make the initial differential diagnosis. If a ganglion was suspected within the deep structures of the foot, an MRI would be useful diagnostic tool should surgery be a consideration, to help identify its location, size and mass.
Should the ganglion lump enlarge & become painful, surgical options can be considered. Marc Blatstein recommends a consult with your physician, and following a detailed history & physical exam, both of you can consider all conservative and surgical options. Then together a treatment plan can be achieved.