👉 A myxomyoma is a type of cancer that occurs in the connective tissue, which includes cells from bones, tendons, and muscles. It's usually caused by a gene called myxin, but it can also develop as a result of other factors such as radiation or chemotherapy. The tumor may grow rapidly and spread to other parts of the body, making treatment difficult. If left untreated, myxomyomas can cause serious complications like pain, weakness, and even death. It