[Hashimoto's thyroiditis and monoclonal gammapathy (two cases) (author's transl)].

: The authors describe two cases of Hashimoto's thyroiditis with a monoclonal dysproteinemia (IgG lambda in one case and IgG kappa in the other). They show that the antithyroid activity (anti-microsomial in the first case, anti thyroglobulin in the second case) is not carried by the abnormal gammaglobulin. The two diseases, therefore, appear to be separate but can both be considered as the consequence of a particular immunological state.