A mass suspected to be malignant can be considered in terms of its characteristics, growth rate, secondary changes, systemic effects, and pathologic findings. 1. Characteristics: malignant tumors are non-enveloped, hard, irregular in shape, destroying surrounding tissues and limiting movement. 2. Growth rate: malignant tumors grow faster. 3. Metastasis: malignant tumors can have lymphatic and hematogenous metastasis. 4. Secondary changes: malignant tumors may have bleeding, necrosis, ulceration and so on. 5. Systemic effects: malignant tumors will have greater systemic effects, which will destroy the tissues of primary site or metastatic site and cause corresponding symptoms, and patients with advanced stage may have weight loss, malnutrition, emaciation and other malignant states. 6. Pathological findings: malignant tumors may have malignant pathological manifestations, and may also be diagnosed with the aid of imaging and laboratory tests. If the mass is considered to be malignant, it should go to the hospital in time for clear diagnosis and reasonable treatment.