[Isolated thyroid gland sarcoidosis and hyperthyroidism]

A case of isolated sarcoidosis of the thyroid gland, associated with hyperthyroidism, is reported in a 28-year-old male patient whose thyroid was removed for hyperthyroid multinodular goitre. Histology revealed a regressive adenoma and sarcoidosis in non-adenomatous thyroid residue. Further diagnosis, therapeutic management and a 3-year follow-up did not disclose any specific changes or involvement of other tissues. Isolated thyroidal sarcoidosis with hyperthyroid alterations are extremely rare and mostly chance findings; simultaneous occurrence of thyroid sarcoidosis and hyperthyroidism may be a symptom of gland infiltration for which an adequate explanation is still lacking.