Riedel's thyroiditis leading to severe but reversible pituitary failure.

This patient with histologically proved Riedel's thyroiditis had hypothyroidism of sufficient severity to cause panhypopituitarism, and it was this which first brought him to medical attention. The beneficial effects are described of surgery in relieving severe dysphagia and stridor, and of prednisone in softening and shrinking the hard neck mass. The extent of pituitary failure, and the degree of recovery on treatment with thyroxine are reported, together with details of 4 other cases of Riedel's thyroiditis seen by one of the authors (S.T.).