METHODS A 86-year-old woman was hospitalized two days before death. Her past history included essential hypertension and joint pain. Electrocardiography and laboratory findings revealed an acute myocardial infarction. Chemical laboratory examination demonstrated hyperthyroidism. The x-ray of the chest showed a tumor-like mass in the right lung and a nodular goiter with focal changes. Sonographically a tumor in the left colon was diagnosed. Inspite of intensive care the patient died two days later of cardiogenic shock. The autopsy revealed a transmural myocardial infarction with rupture of the heart wall. An adenocarcinoma of the rectum infiltrating the perirectal fatty tissue was diagnosed. Metastases were absent. Additional to an eutopic nodular goiter there was ectopic thyroid tissue in the lung, as a tumour mass under the visceral pleura, in the pelvic cavity and in the skeleton. The histologic findings revealed a close resemblance to the thyroid gland in normal anatomical position. In small foci in the eutopic and ectopic thyroid tissues there were signs of hyperthyroidism. There was no evidence of malignancy. CONCLUSIONS One should always keep in mind that manifest hyperthyroidism, not explicable on the grounds of the thyroid findings in normal anatomical position can point to ectopic (multilocular) thyroid tissue, especially when there are "tumours" of uncertain origin.