Cancerous lumps on the arm are usually characterized by pain, enlargement of the lump and lack of blood supply, and require prompt medical treatment. When a lump on the arm becomes cancerous, its characteristics mainly include pain in the affected area and enlargement of the lump. The rapid growth of the lump and the pulling of the periphery can cause pain. Tumors often originate from some tissues, for example, when they are neurogenic tumors, they are usually accompanied by percussion pain or radiating pain in the upper limbs, and even cause local cascade-like phenomenon. However, if the tumor originates from muscle tissue, its cancerous feature is usually asymptomatic enlargement, and the enlarged muscle may cause compression symptoms, such as compression of blood vessels will lead to venous reflux in the upper limb causing arterial blood supply insufficiency, and compression of nerves will lead to pain in the upper limb, and so on.