Unexplained lumps in any area of the body are a cause of concern for many individuals. One such common complaint is the presence of a lump on the sternum in the chest. Although individuals may fear a tumor or some other serious cause, in a large percentage of cases the most probable explanation for a sternum lump is found in a normal body part: the xiphoid process. Other issues such as hernias or tumors may be responsible in some cases, however.
The sternum is one of the primary bone structures in the chest. This structure runs vertically through the middle of the upper body. Its primary function lays in anchoring and connecting the ribs. The sternum begins with a dip at the base of the throat called the sternal notch. The resulting V-shape may feel like one or two knots. These lumps are normal.
Around roughly the center of the chest, the sternum ends in a bone and cartilage protrusion. The protrusion is known as the xiphoid process or xiphisternum, and different individuals have varying sizes and shapes of the structure. In some individuals, the xiphoid process is more prominent and sticks out away from the chest. This anatomical feature may feel like a hard lump on the sternum, especially if an individual is in a reclining position. Weight loss may also cause the xiphoid process to become more noticeable.
The xiphoid process is the likeliest explanation for many concerns regarding a sternum lump or sternum knot, but on occasion a medical issue may facilitate a lump on the sternum. Hernias are another common cause for body masses. These conditions result when part of an organ pushes against or even through the internal barrier that houses it. In the case of a lump on the sternum, protrusion of the stomach or the intestines may create the sensation. This type of hernia may be soft or hard and have associated pain, and it may be caused by a birth defect or by overexertion of the related bodily area.
In rare cases, a lump on the sternum may result from a tumor. Such masses found in the sternum are often benign or non-cancerous. A cancerous tumor around the sternum usually occurs due to a malignancy’s spread from a neighboring structure like the lungs. Either tumor type may or may not feature chest pain and fever as additional symptoms, depending on the size and precise location of the mass. Sternum tumors are one of the least common types of cancer.