Lesions often vary in their severity ranging from serious to harmless. Often found on the skin, lesions can also emerge on the brain or various bones. Skin lesions are first categorized by whether they’re cancerous (a malignant lesion) or non-cancerous (a benign lesion). After doctors determine whether the cause of the lesion is cancer, they move forward with defining the lesion by their patter, location or size. While brain and bone lesions are categorized similar to skin lesions, they cannot be detected by the human eye and require X-rays or MRIs to locate and diagnose the lesion. Depending on the type and location of the lesion, surgery may be required. Physical therapists are key to postoperative recovery, especially with bone lesions that require surgery.