An armpit lump, or axillary lump, is a swelling or bump that forms under the arm. While many are benign, some may signal an underlying condition requiring medical attention. This guide explores potential causes and when professional evaluation is advisable.
Understanding Potential Causes
Armpit lumps can arise from various factors, often originating from the body’s immune response or localized skin issues. One common cause is the swelling of lymph nodes, which are small, oval structures in the lymphatic system. These nodes filter out germs and abnormal cells. When the body fights an infection, such as the flu, mononucleosis, or a vaccine reaction, armpit lymph nodes can enlarge and become tender.
Cysts are another frequent cause of armpit lumps. These are typically harmless, fluid-filled sacs that can appear under the skin. Examples include epidermal cysts or sebaceous cysts, which often feel smooth and movable, and are usually painless unless infected or inflamed. Issues with hair follicles can also lead to lumps; folliculitis (inflamed hair follicles) or an abscess (pus collection) can manifest as tender, painful lumps. Hidradenitis suppurativa, a chronic inflammatory skin condition affecting sweat glands, can also cause painful, boil-like lumps that may fill with pus.
Benign fatty tumors called lipomas are also common. These lumps are typically soft, movable, and generally do not cause pain unless they press on nerves. Ingrown hairs, where a hair curls back into the skin after shaving or waxing, can result in small, sensitive bumps that may be discolored and itchy.
Less commonly, an armpit lump can be a sign of a more serious condition. Breast tissue extends into the armpit, and a lump in this area could indicate breast cancer. Such lumps might feel firm or hard, be irregular in shape, and may or may not be painful. Lymphoma, a cancer of the lymphatic system, often presents as a painless swelling of lymph nodes in the armpit, neck, or groin. Other cancers may also spread to the armpit lymph nodes.
Key Characteristics to Observe
When you discover an armpit lump, paying attention to its characteristics provides useful information for a healthcare professional. Observe if the lump is changing in size or growing. The presence and nature of pain are also important; some lumps are painful to the touch, while others cause no pain. Painful lumps are often associated with infections or allergic reactions.
Consider the lump’s mobility. Some lumps move freely under the skin when touched, while others are fixed in place. The texture and consistency of the lump are also key details; it could feel soft, rubbery, firm, or hard. For instance, cysts or infected lymph nodes may feel softer and movable, while cancerous lumps are more likely to be firm or hard with irregular edges.
Any changes to the skin over the lump should be noted, such as redness, warmth, dimpling, or discoloration. Additionally, be aware of other associated symptoms throughout your body. These can include fever, night sweats, unexplained weight loss, persistent fatigue, or generalized itching. The lump’s duration, whether it appeared suddenly or has been there for a while, also provides context.
When to Seek Medical Evaluation
While many armpit lumps are not serious and may resolve on their own, it is prudent to seek medical evaluation for certain characteristics or persistent lumps. Consult a healthcare professional if the lump is new, growing, or changes in a concerning way. A painful, hard, or fixed lump also warrants prompt medical attention.
Immediate consultation is advisable if the lump is accompanied by other concerning symptoms, such as fever, unexplained weight loss, night sweats, or skin changes like redness or dimpling. Even if a lump seems benign, any armpit lump that does not resolve within a few weeks should be evaluated by a doctor. It is difficult to determine the cause without further testing.
The Diagnostic Process
The diagnostic process typically begins with a thorough medical history and physical examination. The doctor will ask about your symptoms, recent infections, changes to the lump, and overall medical background. They will then manually examine the lump and surrounding areas, assessing its size, consistency, texture, and mobility. This initial assessment helps guide the next steps.
To further evaluate the lump, imaging tests are often utilized. An ultrasound is frequently the first imaging choice for armpit lumps, providing detailed images of the tissue. If breast cancer is suspected, a mammogram may be performed. For more detailed images, a Magnetic Resonance Imaging (MRI) or Computed Tomography (CT) scan might be ordered.
The definitive diagnostic step is often a biopsy, where a tissue sample from the lump is taken for laboratory analysis. Common types include fine-needle aspiration (collects cells with a thin needle) or core needle biopsy (removes a small tissue cylinder). Sometimes, an excisional biopsy, removing the entire lump, may be performed. Blood tests may also be ordered to check for infection, inflammation, or other systemic issues. Treatment depends on the diagnosis, ranging from antibiotics for bacterial infections to surgical removal for benign growths, or specific cancer treatments if malignancy is found.