Neoplasms are defined as autonomous new growths that proliferate continuously without control, resemble healthy cells from which they arise, have no orderly structure, serve no useful function, and continue growing even after the stimulus for growth stops. They can be classified as benign or malignant based on their behavior. Diagnosis involves biopsy, radiology, or exfoliative cytology. Treatment may include surgery, chemotherapy, radiation therapy, immunotherapy, or other approaches. Surgery can be used for definitive treatment if the tumor is localized, for palliative purposes to increase quality of life, or in combination with other therapies.