Fatal myxedema pericarditis in a Christian Scientist

A case of fatal cardiac tamponade due to myxedema pericarditis is reported. The woman, a 54-year-old Christian Scientist, had never sought medical care and died at home. The pericardial sac occupied most of the thorax and contained 2,270 mL of fluid. A thick, shaggy, fibrinous exudate on the pericardium contained abundant cholesterol clefts typical of chronic effusion and myxedema. Thyroid function tests on postmortem blood revealed profound hypothyroidism, and the thyroid was atrophied, with the histologic appearance of primary atrophic thyroiditis. Pericardial effusion is common in myxedema, but cardiac tamponade is rare, only 13 cases being previously reported, none of which was fatal.