Discovering a lump on your shoulder can be concerning. While many such growths are benign (harmless), understanding potential causes can help alleviate anxiety and guide you on when to seek medical advice.
Common Benign Causes
Lipomas are a frequent benign cause of shoulder lumps. These soft, fatty lumps develop just under the skin, feeling rubbery or doughy and movable. They are slow-growing and usually painless unless they press on nerves or blood vessels.
Cysts are another common benign lump on the shoulder. These closed sacs of tissue may contain fluid, air, or pus. Epidermoid cysts, for example, are painless, flesh-colored sacs filled with keratin, often forming from clogged hair follicles or severe acne.
Swollen lymph nodes can appear as lumps in the shoulder or armpit. As part of the immune system, they often enlarge in response to infection. These lumps may be tender or painful and accompanied by other signs of infection like fever.
Muscle knots, or myofascial trigger points, are tense muscle fibers forming painful nodules. They occur in the shoulder from muscle overuse, stress, or poor posture, causing localized inflammation and discomfort. They often feel like a tight, bumpy area within the muscle.
Benign tumors, like fibromas, are less common but can cause shoulder lumps. These non-cancerous growths are composed of fibrous tissue. While generally harmless, any new growth should be evaluated by a healthcare professional.
Other Potential Causes
Ganglion cysts are fluid-filled sacs that form near joints or tendons. In the shoulder, they can develop from underlying joint or tendon issues, such as osteoarthritis or a labral tear. These cysts are non-cancerous, but can cause pain or discomfort if they press on surrounding nerves.
Bursitis, an inflammation of the bursae (fluid-filled sacs cushioning joints), can result in localized swelling or a lump around the shoulder joint. This condition causes pain and tenderness, particularly with movement.
A hematoma, a collection of blood outside blood vessels, can appear as a lump after a shoulder injury or trauma. This lump may initially be soft and tender, becoming firmer as the blood clots.
In very rare instances, a shoulder lump might indicate a malignant tumor, such as a soft tissue sarcoma or lymphoma. Soft tissue sarcomas are rare cancers forming in connective tissues like muscle, fat, or nerves. These lumps may initially be painless but can grow and cause pain if they press on nerves or muscles. Lymphoma, a cancer of the lymphatic system, can also cause enlarged lymph nodes that may feel firm, rubbery, and sometimes movable. Unlike common swollen lymph nodes from infection, lymphoma-related lumps may not be painful.
When to Consult a Doctor
While many shoulder lumps are benign, any new or unexplained lump should be evaluated by a healthcare professional. Several “red flag” symptoms warrant immediate medical attention. These include a lump that is rapidly growing or changing in size.
Pain, redness, or warmth around the lump also warrant medical attention, as these could indicate infection or inflammation. If the lump feels hard or immovable, or is larger than five centimeters (roughly the size of a golf ball), it should be checked. Changes in the color or texture of the overlying skin, such as scaly patches, are also important.
Associated symptoms like unexplained weight loss, fever, or night sweats, particularly with an enlarged lymph node, should prompt medical evaluation. If the lump interferes with arm movement or causes numbness or weakness, seek professional advice.
What to Expect at the Doctor’s Office
When consulting a doctor about a shoulder lump, the process begins with a thorough physical examination. The doctor will feel the lump, assessing its size, texture, mobility, and tenderness. They will also ask about its history, including when it was noticed, how it changed, and any other symptoms.
Depending on initial findings, the doctor may recommend imaging tests. An ultrasound is a first-line diagnostic tool, being quick, non-invasive, and determining if the lump is solid or fluid-filled. For detailed soft tissue images, an MRI scan may be ordered. If a bone issue is suspected, an X-ray or CT scan might be used.
In some cases, especially if a more serious condition is suspected, a biopsy may be performed. This involves taking a tissue sample from the lump for laboratory analysis to determine its nature. Information from these examinations and tests helps the doctor reach an accurate diagnosis and discuss management options, from observation to treatment or removal.