Cancer of the foot can appear in many forms, including small masses, cysts and lesions. The most common kinds of foot cancer are malignant melanoma, neoplastic disorders (tumors) and giant cell tumors. Some tumors may be painless, while others can cause broken bones, dull aches and numbness or tingling in the foot. Treatment may not be necessary if the tumor is non-cancerous and doesn’t cause any side effects. If the tumor causes pain and/or is malignant, then surgery to excise the tumor may be required, followed by possible radiation therapy and chemotherapy. Routine monitoring is required for both noncancerous and malignant tumors to make sure that the tumor does not continue to grow or spread.