Sarcoidosis and Hashimoto's thyroiditis--a chance occurrence?

We present a case of pulmonary sarcoidosis associated with Hashimoto's thyroiditis. This association has been reported previously and may be purely coincidental. However, in light of current knowledge about the immunoregulatory defects postulated for sarcoidosis and for Hashimoto's thyroiditis, three other possibilities that may explain this association in our patient, are discussed.