Discovering a lump under the jaw can be unsettling. While a lump in this area can sometimes signal a serious condition, many instances are benign and result from common, less concerning issues. This article provides general information about potential causes of a jaw lump and guidance on when medical attention is important.
Understanding the Anatomy of the Jaw and Neck
The area under the jaw and in the upper neck contains several structures that can develop a lump. Lymph nodes are small, bean-shaped glands that are part of the immune system and are found throughout the body, including under the jaw. Salivary glands, such as the submandibular glands, are also located in this region and produce saliva.
Various tissues like muscles, fat, and skin are also present beneath the jawline. Each of these structures can become swollen, inflamed, or develop growths, leading to a lump.
Common Inflammatory and Infectious Causes
Lumps under the jaw frequently arise from inflammatory or infectious processes. Swollen lymph nodes are a common cause, often indicating that the body is actively fighting an infection. These nodes can enlarge in response to illnesses such as the common cold, influenza, strep throat, or even infections originating from teeth or ears. Infected lymph nodes typically feel soft, movable, and may be tender or painful.
Issues with the salivary glands can also lead to lumps. Sialadenitis refers to inflammation of a salivary gland, which can result from bacterial or viral infections like mumps. This condition often causes swelling and pain in the affected gland. Another common problem is sialolithiasis, where small stones form in the salivary ducts, blocking saliva flow and causing the gland to swell, especially during or after eating.
Abscesses represent another infectious cause, forming when pus accumulates in a localized area due to a bacterial infection. These collections can develop in the soft tissues under the jaw, feeling tender and warm to the touch. Dental infections, particularly from an infected tooth root, can sometimes spread and create an abscess in the jaw or neck region. This type of lump often presents with noticeable pain and redness of the overlying skin.
Cysts and Benign Growths
Beyond infections, non-cancerous formations like cysts and benign growths can appear as lumps under the jaw. Cysts are sacs filled with fluid, air, or other material. Sebaceous cysts form when a hair follicle or oil gland becomes blocked, creating a slow-growing, movable lump under the skin. Epidermoid cysts are similar, resulting from skin cells trapped beneath the surface.
Congenital cysts, present from birth but sometimes noticeable later, can also appear under the jaw. Branchial cleft cysts arise from remnants of embryonic development in the neck and can appear along the side of the neck or near the jawline, sometimes becoming infected. Thyroglossal duct cysts, another congenital type, typically appear in the midline of the neck but can sometimes be located closer to the jaw.
Lipomas are another common type of benign growth, consisting of a collection of fatty tissue. These lumps are generally soft, feel rubbery, are easily movable under the skin, and are typically painless. Less common benign tumors include fibromas (fibrous tissue) or neurofibromas (nerve tissue).
When a Lump is More Concerning
While many jaw lumps are benign, certain characteristics warrant medical evaluation. A lump that feels hard, is fixed in place, or does not move freely under the skin is concerning. Rapid growth or the sudden appearance of a new lump also requires prompt medical assessment.
Persistent or worsening pain with the lump is another important symptom. Other systemic symptoms, such as unexplained weight loss, night sweats, persistent fever, or unusual fatigue, can indicate a more serious underlying condition. Difficulty swallowing, breathing, or speaking, if associated with the lump, requires urgent medical attention.
Changes in the overlying skin, such as persistent redness, ulceration, or dimpling, are also concerning. Any lump persisting for more than a few weeks without an obvious cause, like a recent infection, should be evaluated. Any lump discovered in an infant or young child should always be assessed by a pediatrician.
The Diagnostic Process
The diagnostic process for a jaw lump typically begins with a thorough medical history and physical examination. The doctor will ask about the lump’s duration, associated symptoms, and the patient’s health history. During the physical exam, the doctor carefully feels the lump, assessing its size, consistency, mobility, and tenderness, and examines surrounding head and neck areas.
Following the initial assessment, imaging tests are often used to gain a clearer picture. An ultrasound is often the first choice due to its non-invasive nature and ability to differentiate between solid and fluid-filled masses. Depending on findings, a CT scan or MRI may provide more detailed images of neck structures, determining the lump’s precise location and relationship to surrounding tissues.
Blood tests are sometimes performed to check for infection or inflammation, which can help confirm an infectious cause. However, a definitive diagnosis, especially for solid masses, often requires a biopsy. A fine needle aspiration (FNA) is a common biopsy procedure where a thin needle collects a cell sample from the lump. A pathologist then examines this sample under a microscope to determine if the lump is benign or malignant.