Clinical experience in the diagnosis of 127 papillary thyroid microcarcinomas

To investigate the difficulties in the diagnosis of thyroid microcarcinoma and to present the results of delaying diagnosis for these patients, we retrospectively analyzed the clinical information of 1259 thyroid carcinoma patients in one medical center. During a period of 20 years, from January 1977 to June 1997, 1259 thyroid cancer patients, including 921 papillary thyroid carcinoma patients, who received treatment and were followed-up at Chang Gung Medical Center in Linkou, Taiwan, were evaluated for inclusion in the study. Of these patients, 127 (13.2%) were diagnosed as having thyroid microcarcinoma. Forty-five patients were diagnosed as malignancy or suspicious malignancy preoperatively with ultrasonography and fine needle aspiration cytological examinations. In the analysis, the 127 thyroid microcarcinoma patients who received surgical treatment could be divided into four groups. Group I: patients with thyroid microcarcinoma with hyperthyroidism or hyperparathyroidism, in most of whom (except four patients) the thyroid microcarcinoma was found incidentally during the operation (28 cases). Group II: thyroid microcarcinoma in benign larger thyroid nodule or multinodular goiter, or thyroid microcarcinoma in coexistence with nodule goiter in one patient. The thyroid microcarcinomas in this group were found incidentally except in five patients (58 cases). Group III: thyroid microcarcinoma which could be detected as thyroid nodule preoperatively (28 cases). Group IV: thyroid microcarcinoma presented with neck lymph node metastases or distant metastases of the thyroid carcinoma (13 cases). Median follow-up period of these 127 patients was 4.7 years. During the follow-up period, two patients died, including one patient in group IV who died of skull metastasis with brain invasion. Another patient died of stroke, which was, however, not related to thyroid carcinoma. In conclusion, most thyroid microcarcinoma patients experienced rather benign clinical courses, but for patients with thyroid microcarcinoma with distant metastases, aggressive surgical treatment followed by radioactive ¹³¹I treatment is indicated.