From a group of 134 patients with complete documentation before goitrectomy the authors selected 10 histologically defined cases of (A) simple colloid nodular goitre, (B) toxic parenchymatous goitre type GB and (C) autoimmune thyroiditis. Marked hormonal suppression was achieved in group B by thyrostatic therapy, as compared with A and C, the autoantibody titres (TGAb and TMAb) differentiated the groups. The authors examined the interleukin 6 concentrations and those of its soluble receptor (IL-6, IL-6R), of the tumour necrotizing factor alpha (TNF-alpha) interferon gamma (IFN-gamma) and of adhesion molecules ICAM-1 and VCAM-1. Plasma values were, except for not very significant differences, similar in all groups and ruled out a marked effect on tissue levels. The most remarkable finding in the homogenate of a peroperative excision were low IL-6, IL-6R and adhesion molecule values in group A, as compared with B and C and the absence of differences in TNF-alpha values between groups and in particular markedly higher IFN-gamma values in group B which supports theories on the etiopathogenetic role of this cytokine in GB disease. The pilot study is part of the preparation of in situ hybridization of mRNA for diagnostically usable cytokines.