This document discusses the differential diagnosis and management of head and neck swellings. It notes that while some masses are cancerous, many are benign. Common benign causes include cysts, infections of lymph nodes or salivary glands, and benign tumors of structures like the thyroid. Malignant causes can be primary tumors of head and neck regions or secondary cancers spread from other areas. Diagnosis involves medical history, physical exam, imaging tests, and biopsy. Treatment depends on whether the mass is benign or malignant and may involve surgery, radiation, chemotherapy, or medication.