What is an ear lump? An ear lump is a protuberance or localized area of swelling that can occur anywhere on the ear. Other terms used to describe the various types of lumps include bump, nodule, tumor and cyst. Lumps can be caused by any number of conditions, including infections, inflammation, tumors or trauma. Depending on the cause, ear lumps may be single or multiple, soft or firm, painful or painless. They may grow rapidly or may not change in size. Common sites for ear lumps include your ear canal, ear lobe, and behind your ear. Ear lumps can be caused by exostoses and osteomas, which are types of tumors that grow in the bones of the ear canal. An ear lump and tenderness in the bone behind your ear, along with pain and swelling, could indicate mastoiditis (infection of the mastoid bone). Ear lumps due to local infectious causes may appear as boils or abscesses. Many types of infections cause the lymph nodes behind and below the ears near the jawbone to enlarge and feel like lumps. Traumatic causes of lumps range from bug bites to severe injuries that can produce localized collection of blood in the tissues (hematoma). Both benign and malignant tumors of the skin, soft tissues, or organs can sometimes feel like lumps. In these cases, either a biopsy or surgical removal of the lump can determine whether cancer is present. Cysts, which are fluid-filled, sac-like structures that can form in various parts of the body, often feel like lumps. Some cysts may be present at birth, while others develop as a result of inflammation, tumors, or wear and tear over time. Sebaceous cysts are benign lumps filled with pus, dead skin cells, and excess oil. Ear lumps caused by infection, inflammation or trauma are usually temporary and subside as the underlying condition resolves. Ear lumps that persist or continue to grow over time may signal more serious conditions, such as tumors. A lump near the ear that is associated with a head injury may signal bleeding in the brain or another emergency and may have life-threatening complications. Seek immediate medical care (call 911) if you have a lump near your ear as a result of head injury. If you have any ear lump that is persistent or causes you concern, seek prompt medical care.