A VARIANT OF ADENOMATOUS GOITER WITH CHARACTERISTIC HISTOLOGY AND POSSIBLE HEREDITARY THYROGLOBULIN ABNORMALITY

A variant type of adenomatous goiter was identified in 24 of 2160 pati ents with adenomatous goiter who underwent thyroidectomy. The characte ristics of the thyroid gland in these 24 patients included large goite r, small follicles, scant colloid, and columnar follicular cells conta ining yellow-green granules on hematoxylin-eosin staining. The thyroid gland was slightly orange-red, and electron microscopic examination s howed abundant lysosomes with colloid droplets. When comparing the fea tures of this group with those of 24 patients with common adenomatous goiter, the incidence of familial predisposition to thyroid diseases i n the former group was higher. The age at the time of detection of goi ter was lower, i.e. 17 +/- 15 vs. 44 +/- 17 yr (P < 0.001, variant typ e vs. common type), the serum total T-4 concentrations were lower (84 +/- 21 vs. 103 +/- 18 nmol/L; P < 0.01), and the serum TSH concentrati ons were higher (2.4 +/- 2.1 us. 1.0 +/- 0.9 mU/L; P < 0.01). Thyroid radioiodine uptake was remarkably increased (49 +/- 22 vs. 16 +/- 9%; P < 0.001), and lower levels of serum thyroglobulin were noted (33 +/- 51 us. 484 +/- 603 mu g/L; P < 0.01). The thyroglobulin content was l ow in the thyroid gland studied. The data suggest that the etiology of this variant type of goiter is a hereditary abnormality in thyroglobu lin synthesis, and this type of goiter may be distinguished from commo n adenomatous goiter by the characteristic morphology of the thyroid g land in addition to clinical findings.