Eurysternum (extra-wide sternum)--a rarely recognized developmental anomaly. Scintigraphic appearances.

A rarely recognized extra-wide sternum was demonstrated by Tc-99m methylene diphosphonate bone scans in two adult patients. One patient was a 53-year-old man with prostate cancer who had no sternal symptoms or known sternal deformity. The second patient was a 41-year-old man with carcinoma of the lung whose extra-wide sternum was associated with a pectus excavatum deformity involving the lower half of the mesosternum (corpus sternum). A proper name for this developmental abnormality, "eurysternum" (eury-Greek word meaning broad; wide), is suggested. Two other patients, one with another type of wide sternum and another with a mesosternal foramen (fenestra sternii) deformity are also described. Related embryology and developmental anatomy of the sternum are reviewed.