Sternal Lesion
A sternal lesion is any focal abnormality identified in the sternum, the long flat bone at the front of the chest. Sternal lesions can be benign or malignant and may arise from the bone itself, from nearby cartilage and soft tissues, or as a result of trauma, infection, inflammation, or spread of cancer from elsewhere in the body. Many sternal lesions are discovered incidentally on chest imaging done for other reasons. Imaging features—along with the patient’s age, symptoms, and broader medical context—help determine the most likely cause and whether further evaluation is needed.
What is it?
The sternum, or breastbone, is the long flat bone in the center of the front chest. It connects to the ribs through cartilage on each side and helps anchor and protect the heart, lungs, and major blood vessels behind it. The sternum has three parts: the manubrium (upper portion), the body (middle portion), and the xiphoid process (small lower tip). A sternal lesion is any focal abnormality identified in one of these parts of the bone, and because the sternum sits centrally on chest imaging, lesions here are sometimes noticed even when they cause no symptoms.
Sternal lesions can arise from many different processes. Benign causes include healing or healed sternal fractures (often related to falls, vehicle accidents, CPR, or osteoporosis), bone islands (small areas of dense bone within the marrow), bone cysts, hemangiomas, fibrous dysplasia, and bony changes from prior surgery (especially after cardiac surgery, which often leaves wires, hardware, and remodeled bone). Inflammatory and infectious causes include osteomyelitis of the sternum, abscesses (which can rarely complicate surgery or intravenous drug use), and inflammatory conditions such as SAPHO syndrome and certain arthritides.
Malignant sternal lesions are less common but important to recognize. Metastatic disease is the most common malignant cause and may arise from cancers of the breast, lung, kidney, prostate, or other organs. Multiple myeloma and lymphoma can also involve the sternum, sometimes as part of more widespread bone disease. Primary bone tumors of the sternum—such as chondrosarcoma, osteosarcoma, and Ewing sarcoma—are uncommon but well-recognized. Direct extension of nearby tumors, such as breast cancer or mediastinal masses, can also produce sternal lesions.
Symptoms depend on the type, size, and behavior of the lesion. Many sternal lesions cause no symptoms and are discovered incidentally on chest imaging done for unrelated reasons. When symptoms occur, they may include localized pain or tenderness over the breastbone, a visible or palpable lump, swelling, or pain that worsens with breathing, coughing, lifting, or pressure. Pathologic fractures—where a weakened area of bone breaks with minor or no trauma—can cause sudden, sharp pain. Some sternal lesions are accompanied by systemic symptoms (such as fatigue, weight loss, or fever) that reflect an underlying condition like infection or malignancy.
CT of the chest is the primary imaging test for evaluating a sternal lesion because it provides detailed views of the bone and any associated soft-tissue components, can identify features that suggest a benign or aggressive pattern, and shows the relationship to nearby structures such as the heart, lungs, and major blood vessels. MRI is particularly useful for evaluating the bone marrow, soft-tissue extension, and involvement of nearby structures. Bone scan and PET/CT can assess metabolic activity and identify other lesions throughout the skeleton. In some cases, image-guided or surgical biopsy is needed to establish a definitive diagnosis, especially when imaging findings are suspicious or the patient has a known cancer.
Important to Know
For many sternal lesions—particularly small, stable, classically benign findings—no specific treatment is needed, and follow-up may be limited or unnecessary. Healing fractures generally require time, pain management, and avoidance of activities that worsen pain. Stable bone islands, small hemangiomas, fibrous dysplasia, and post-surgical changes are usually monitored only if there is uncertainty or concerning features.
When a sternal lesion appears more aggressive on imaging, is causing significant symptoms, is rapidly growing, or is found in a patient with a history of cancer, further evaluation is generally warranted. This may include additional imaging, blood work, and biopsy. Treatment is then directed at the specific underlying diagnosis: antibiotics and possible drainage for infection; surgery for symptomatic benign tumors; and a combination of surgery, radiation, chemotherapy, immunotherapy, or targeted therapy for malignant lesions. Pathologic fractures may require pain management, stabilization, radiation, or treatment of the underlying cause.
Because the sternum sits close to the heart and great vessels, evaluation and treatment of sternal lesions are often coordinated by a multidisciplinary team that may include thoracic surgery, orthopedic oncology, medical and radiation oncology, interventional radiology, and primary care.
Red flag symptoms include severe or rapidly worsening chest pain, pain that wakes the patient at night, a rapidly enlarging mass, unintended weight loss, persistent fever, severe pain after minor trauma, redness or drainage over a recent surgical site, or new neurological or breathing symptoms. These warrant prompt medical evaluation.