Definition: A mycetoma is a type of cancer that occurs in the bone. It's caused by a fungus called Mycobacterium, which can grow inside the cells of your bones and spread to other parts of your body. The symptoms of a mycetoma can include pain or swelling in your joints, difficulty walking, and loss of hair. There are two types of mycetomas: primary and secondary. Primary mycetomas occur when an infection occurs in one part of