A lump next to your neck could be a lipoma or an enlarged lymph node. Lipoma is usually a mass caused by abnormal growth of fat under the skin, with an outer envelope and fatty tissue inside. Small lipomas do not cause pain and can be followed up. Large lipomas can be lobulated and need to be surgically removed if they are aesthetically displeasing, if they cause pressure, or if they bleed internally and cause pain. If it is an enlarged lymph node, it may be caused by inflammation and infection, which usually manifests as enlarged and painful lymph nodes, and can be treated with oral antibiotics, such as cefradine or cefixime.