CLEAR NUCLEAR-CHANGES IN HASHIMOTOS-THYROIDITIS - A CLINICOPATHOLOGICAL STUDY OF 12 CASES

Histologic sections of thyroid glands resected from 12 patients with H ashimoto's thyroiditis have been studied in which areas were present s howing clear nuclear changes such as those seen in papillary carcinoma . The patients' ages ranged from 28 to 78 years (mean = 57.3); 11 were women and one was a man. The lesions presented as focal, ill-defined areas displaying clear nuclear changes of the cells within otherwise w ell-circumscribed adenomatous nodules, or as small clusters of cells s howing the characteristic clear nuclear features randomly admired with the Hashimoto's elements. Histologically, the lesions were characteri zed by a range of nuclear features that included optically clear nucle i, prominent cytoplasmic invaginations with intranuclear cytoplasmic i nclusions, and occasional nuclear grooves. In two cases, focal papilla ry formations were seen that were lined by cells with optically clear nuclei. In two other cases, well-circumscribed nodules bearing the arc hitectural features of trabecular hyalinizing adenoma with focal clear nuclear changes were also present. In three cases, small (<0.5 cm) we ll-circumscribed nodules bearing cytological features indistinguishabl e from those of microscopic papillary carcinoma were also present in a ddition to the areas of clear nuclear change. Follow-up of 1.5 to 19 y ears (mean = 9 years) showed no evidence of recurrence or metastases i n any of our patients. Our study appears to indicate that thyroid foll icular epithelium in patients with Hashimoto's thyroiditis may exhibit a range of clear nuclear changes similar to those encountered in papi llary carcinoma. Such changes may represent another form of response o f follicular epithelium to the underlying autoimmune process with poss ible premalignant connotation. However, they should be interpreted in context with the rest of the findings within the involved gland to avo id an overdiagnosis of malignancy.