Sternal muscle: a mammographic finding

The sternal muscle is an uncommon anatomic variant of the chest wall usually located only in one side along the sternal border. The superficial location of the muscle sometimes presents a mammographic finding as an asymmetric density in the middle and deep area on the cranio caudal projection, resembling a malignant lesion. Conclusive diagnosis is provided by CT and MR showing the sternal muscle. It is important to know this variant in order to reduce the number of patients undergoing new mammographic studies, any other imaging procedure or biopsy. (Author) 4 refs