A bulge on the top of the neck may be caused by enlarged lymph nodes, lipoma, fibroma, sebaceous cysts and other reasons. 1. Enlarged lymph nodes: such as lymphoma, lymphadenitis and other diseases, can lead to swollen lymph nodes protruding from the skin surface, manifested as a bulge on the neck. 2. Lipoma: caused by abnormal proliferation of fat cells, soft in texture, can occur in the neck, back, abdomen and other parts of the body, and may appear as a lump bulging phenomenon. 3. Fibroma: the cause is unknown, can occur in all parts of the body, manifested as smooth surface papules, nodules, can be accompanied by pain. 4. Sebaceous cysts: caused by sebaceous gland discharge abnormality, secretion accumulation, if the sebaceous cyst volume is large, you can see the bulge on the skin surface. It is recommended that people with a bulge on the top of the neck go to the hospital in time to clarify the cause of the disease and standardize the treatment under the guidance of the doctor.