[Fine needle biopsy of "cold" struma nodules in 4555 patients of an endemic goiter area. Results and clinical significance].

Over a period of 8 years, thin needle biopsies of hypofunctional, scintigraphically cold goiter nodules were performed in 4555 patients. 1076 underwent surgery and cytological diagnoses were thereby histologically confirmed. In 715 patients with normal or degenerative cytological findings, the diagnosis was correct in 95.1%. On the other hand, 8 malignancies, 13 Hürthle-cell adenomas, and 26 cases of Hashimoto's thyroiditis were misdiagnosed. The 8 diagnostic errors in the malignancies were due to puncturing of the wrong nodule in 3 cases and, in 5 cases, due to highly differentiated, partially degenerated, follicular carcinomas. In 322 cases with suspect or malignant cytological findings, 129 malignancies (40%) were confirmed. In most cases, false positive diagnosis was due to histologically atypical adenomas, e.g. Hürthle-cell adenomas. Hashimoto's thryoiditis could be readily diagnosed only in the advanced stage. The clinical diagnosis of de Quervain's thyroiditis can be verified by cytological examination.