A lump on collarbone can make anyone feel concerned, but you should not worry too much right away. In some cases, it is nothing more than benign neoplasm. However, these hard lumps may also indicate something more serious such as malignant neoplasm or tumor-like lesion. Let's find out more about it.

Possible Causes of Hard Lump on Collarbone

Your lump may indicate a self-limiting infection in case it persists for less than three weeks. These types of lumps do not require further evaluation, but it still makes sense to talk to your doctor to be on the safe side. You should be more concerned about a lump that persists for longer than four weeks. Here are some other reasons for a hard lump on the collarbone.

1. Swelling Caused by Lifting Heavy Things

Have you recently lifted, pulled, or pushed something very heavy? That may be the reason why you have developed a lump on collarbone. You may consider taking anti-inflammatory medications to resolve the swelling if necessary. Applying warm compresses may also help in this case. Talk to your doctor if the swelling persists and your pain increases with time.

2. Clavicle Fracture

As the clavicle is a long bone, it may become fractured in the middle. Sometimes, the break occurs where the clavicle bone attaches at the shoulder blade or ribcage. The direct blow to the shoulder may lead to clavicle fractures and cause a lump to appear on the collarbone.

The other common symptoms of clavicle fractures are swelling, bruising, tenderness, pain that will aggravate with shoulder movement, and stiffness in the shoulder. You may also notice a crackling sound when trying to move your shoulder.

3. Aneurysmal Bone Cyst

This is another cause of hard lump on collarbone. It is an osteolytic bone neoplasm, and you will develop a noticeable lump right on the collarbone under this condition. However, it is also possible to develop serum or blood-filled cysts on the bones in the upper arms, legs, spine, or pelvis.

The most common symptoms of aneurysmal bone cyst are decreased range of movement, stiffness in the affected body part, persistent swelling and pain. 

4. Fibromyalgia

This disorder causes serious musculoskeletal pain with bumps and lumps under skin. These non-cancerous bumps or tumors are called lipomas. Usually treatments are not necessary, but you may consider having it removed if the lipoma is painful or grows bigger.

The most common symptoms of fibromyalgia are fatigue, widespread pain, and cognitive difficulties. Some people may also experience headaches, depression and pain in the lower abdomen. 

5. Arthritis

You can develop a hard lump on collarbone due to rheumatoid arthritis or osteoarthritis. You may develop rheumatoid nodules under the skin when you have rheumatoid arthritis. These lumps usually form close to the affected joints and may be as small as a pea or as large as a walnut. Some of these nodules are firm while others may move. The most common symptoms of rheumatoid arthritis are warm, tender, swollen joint, weight loss, fever, and fatigue.

In case of osteoarthritis, which develops due to wear and tear of the protective cartilage on the end of your bones, you develop bone spurs. These bone spurs feel like hard lumps and usually develop around your affected joint. The most common symptoms of osteoarthritis are stiffness, tenderness, pain, grating sensation, and loss of flexibility.

6. Vascular Thoracic Outlet Syndrome

You develop thoracic outlet syndrome when the arteries or veins under the collarbone become compressed. This may lead to the development of a lump near your collarbone.

The most common symptoms of vascular thoracic outlet syndrome are blood clot in arteries or veins in the upper body, discoloration of your hand, swelling and pain in the arm, cold fingers or arms, weak or no pulse in your affected arm, and arm fatigue after activity.

7. Lymphoma

The lymph system is a part of your immune system and the cancer of the lymph system is called lymphoma which can be of many different types. They are usually divided into two main categories: Hodgkin lymphoma and non-Hodgkin lymphoma. You may develop painless lymph nodes in the armpits, neck, or groin because of this disease.

Other main symptoms of lymphoma are fever, unexplained weight loss, pain and swelling in the abdomen, persistent tiredness and weakness, night sweats, and trouble breathing with chest pain.

8. Breast Cancer

The hard Lump on collarbone may sometimes indicate breast cancer. This usually happens when the cancer has spread to lymph nodes in those areas. There may be swelling even before the development of a lump in the breast. Many people do not have any symptoms during the early stage of breast cancer. Some experience symptoms such as a lump in the breast, nipple discharge, nipple changes, skin thickening, breast itching and pain.

9. Chondrosarcoma

It is a malignant mesenchymal tumor and does not usually cause many symptoms. You may not even feel sick with this type of tumor, but there will be a boney bump. It will eventually become painful, and you will also notice swelling and limited movement. Other symptoms of chondrosarcoma include sciatica, thigh/back pain, unilateral edema, and bladder symptoms.