Occult papillary carcinoma of the thyroid gland revealed by cancer pericarditis.

We report a case of hemorrhagic exudative pericarditis in a 41-year-old man which was found to be due to metastatic dissemination of a 4 mm sclerosing carcinoma of the thyroid. Many psammoma bodies were found in the pericardial specimens and malignant cells with folliculoid pattern were observed in the pleural biopsy, arousing suspicion of occult papillary thyroid carcinoma. In the thyroid gland after total thyroidectomy a 4 mm sclerosing carcinoma was found.