Studies on Fine Needle Aspiration Cytology of the Thyroid Gland

Cytological findings of thyroid diseases, especially tumor, were investigated by using the fine needle aspiration cytology. The aspiration was performed with a fine needle (21gauge) and a disporsable plas syringe (20ml). The specimens were stained by Papanicolaou's and May-Giemsa's technique.1, 073 aspirations in 997 patients were performed during 6 years, 1971 to 1976. Following conclusions were obtained:1. In order to know the accuracy of the diagnosis obtained by the aspiration cytology, 51 malignant and 47 benign cases were compared, these cases were histologically confirmed by surgery or autopsy. 45 out of 51 (82%) cases were correct in malignant cases, and 42 out of 47 (89%) in benign cases, 2 false negative and 2 false positive cases were observed.2. Cystic fluid was obtained in about half of 997 patients. 9 of 10 adenocarcinoma cases were correctly diagnosed by the cytology of cystic fluid prior to operation. It was easy to diagnose. for malignancy form centrifused sediment smear of cystic fluid, because cytological characteristics of carcinoma cells were emphasized by degenerative process. Therefore, it should be stressed that not only aspiration cytology from solid tumor but also from cystic fluid is very important.3. The microscopical findings of benign adenoma, cyst, Hashimoto disease, subacute thyroiditis, well differentiated adenocarcinoma and anaplastic carcinoma were examined and analyzed with respect to their cell patterns, cellular details and background features. Compare to the fresh touch smear cells of stomach cancer, it seems that thyroid cancer cell have not so much cellular atipism than stomach cancer cell.4. Intranucleic inclusions were observed in 19 of 33 patients of papillary cancer of thyroid. And they were neither detected in the cases of other types of carcinoma nor in all of benign cases.5. We have never had complications clinically including bleeding, infection and cancer metastasis in our extended experience.