An incidentaloma is a tumor that is found incidentally without clinical symptoms. This study was carried out to evaluate the clinicopathologic characteristics and to offer the optimal diagnostic and therapeutic strategies for surgical treated thyroid incidentaloma.

We reviewed the medical records of 139 consecutive patients who were operated on for incidentally detected thyroid nodules from January 2000 to June 2005, and we retrospectively investigated the clinicopathologic characteristics, preoperative diagnostic methods, operative methods and histologic diagnosis of surgical treated thyroid incidentaloma.

The male-to-female ratio was 1:9.7 (13:126) and the mean age was 45.8 years. The mean tumor size was 1.27 cm and 122 cases (87.8%) were 1.5 cm or less in diameter. 138 patients underwent ultrasonography and 34 patients (24.6%) were diagnosed with malignant nodules. US-guided fine needle aspiration cytology (FNAC) was performed in 118 patients and 42 patients (35.6%) were diagnosed with papillary carcinoma. According to postoperative histologic diagnosis, 70 cases (50.3%) were adenomatous goiter, 14 cases (10.2%) were follicular adenoma and 54 cases (38.8%) were papillary carcinoma. Among the papillary carcinoma, capsular invasion were presented in 3 cases (5.6%) and lymph node metastasis were presented in 5 cases (9.3%). According to the TNM staging, 33 cases (61.1%) were stage I, 16 cases (29.6%) were stage II, and 5 cases (9.3%) were stage? By the AMES scoring system, 2 cases (3.7%) were in the high risk group.

Although most patients with incidental thyroid carcinomas were low stage, their clinicopathologic characteristics were similar to those of general thyroid carcinoma. Therefore, high risk patients with thyroid incidentaloma should have active diagnostic methods performed such as FNAC for confirming the presence of carcinoma.