Thyroid nodules often present diagnostic difficulties, so the misdiagnosis before treatment meets with bad results to the patients. For the pathologic diagnosis of thyroid nodules, needle biopsy was used. Recently fine needle aspiration cytology was introduced as very simple, not danger to the patient and relative high diagnostic accuracy in detecting between benign and malignant thyroid nodules. This retrospective study was undertaken to examine the accuracy of the preoperative aspiration cytology of thyroid nodules in addition to clinical analysis.
We performed a clinical analysis of 131 cases of thyroid nodules who were operated upon at the Department of Surgery, Chungnam National University Hospital from January 1981 to April 1983. Among the 131 cases, preoperative aspiration cytology was performed 61 cases at the Department of Internal Medicine, Chungnam National University Hospital before transferred to Department of Surgery for the operation and the result was compared with final diagnosis taken from biopsy.
The results were obtained as follows:
1) Of 131 cases, 100 cases (76.3%) were benign and 31 cases (23.7%) were malignant and 3 cases of benign nodules were thyroiditis (2.3%).
2) Thyroid nodules were prevalent in 3rd, 4th and 5th decade evenly, and the peak age incidence was in the 4th decade, 39 cases (29.8%).
Male were 13 cases (9.9%) and female were 118 cases (90.1%) and the sex ratio (M: F) was 1 9.1.
3) The duration of palpable thyroid nodules prior to admission were less than 6 months in 50 cases (38.2%) and less than I year in 60 cases (45.8%).
4) The solitary nodules were 124 cases (94.7%) in which 30 cases (25.2%) were malignant tumors.
5) The thyroid scanning in benign cases revealed cold area in 95 cases (96%), hot area in 4 cases (4%) and all malignant case revealed cold area.
6) A comparison of preoperative aspiration cytology and postoperative pathologic diagnosis in thyroid nodules showed 55.6% overall accuracy in differentiation between benign and malignant lesions.
7) In pathologic classification, 100 cases were benign thyroid nodules, among these, cases,
81 cases (81%) were adenomatous goiter, 14 cases (14%) follicular adenoma, 2 cases (2%) Hurthle cell adenoma and remaining 3 cases were thyroiditis and 1 case was chronic thyroiditis.
In 31 cases with thyroid nodules, 17 cases (54.9%) were papillary carcinoma, 9 cases (29%) follicular carcinoma, 4 cases (12.9%) papillary-follicular carcinoma and remaining 1 case (3.2 %) was medullary carcinoma.
8) In benign cases, total lobectomy was performed in 42%, subtotal thyroidectomy was performed in 41.9% in malignant tumors.
The choice of the appropriate treatment of thyroid nodules can be made according to the precise interpretation of the operative findings, particularly the extent of tumor involvement and the characteristics of the tumor in addition to preoperative aspiration cytology. And the frozen section should be utilized for the differentiation of benign and malignant tumor during operation which are hard to distinguish grossly.
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