[Graves' disease with unusual histological findings]

We reported three cases of Graves' disease which showed unusual histological findings featuring solid follicles, multinucleated giant cells and diffuse infiltration of histiocytes as well as lymphocytes in the whole section of the resected thyroid. Characteristics of these three cases were as follows: (1) Clinically, longer duration of the disease and exophthalmos were their prevailing findings. (2) On laboratory data, antimicrosomal antibody showed extremely high titers with 100,000 to 400,000. (3) Their operative findings were different from ordinary Graves' goiters in that colors of the goiter were yellow-red or gray-red, surface was rough and coarse, consistency was firm, and adhesions with the adjacent connective tissue were noted. (4) Postoperative clinical outcome was quite similar to that of ordinary Graves' patients. From these findings, these three cases were considered to be different from either so-called Hashitoxicosis or silent thyroiditis or Graves' disease with granulomatous foci, and it was suggested that these three cases might be a subgroup of Graves' disease or another hyperthyroidism than ordinary Graves' disease. Further accumulation and analysis of such cases will be necessary in order to answer this question.