A small, boomerang-shaped bone found beside the electrical relay station of a 39-year-old man's heart drew wide attention this year. Forensic examiners in Virginia reported it in the American Journal of Forensic Medicine and Pathology as an os cordis, a "heart bone" familiar in cattle but almost never described in people.
That discovery was incidental and unrelated to the man's death. But it points to a far more common and medically important fact: the human heart can grow genuine bone, and it does so most often in diseased valves.
