There are many causes of chest pain, and it is not necessarily only leukemia. For young people or children, sometimes injuries such as those from car accidents, sleeping on the stomach, or accidentally bumping into chair backs or table corners can cause sternal pain. However, persistent sternal pain in children should be carefully examined for the possibility of blood disorders. Of course, this can be ruled out through chest CT scans, or, if necessary, a small sternal biopsy under local anesthesia to check for leukemia.

But for adults, there are many other possible causes of chest pain, such as gastrointestinal ulcers, stomach ulcers, and duodenal ulcers which can radiate to the surrounding area of the sternum causing pain. Additionally, some anatomical organs behind the sternum such as heart diseases, coronary artery disease, and angina can also cause sternal pain. Thymomas, thymus cancer, an enlarged thyroid, and lymphoma can all lead to sternal pain. Other malignant tumors, like lung cancer, if involving the sternum can also cause this pain. Therefore, not all cases of sternal pain are definitely due to leukemia.