In order to examine the diagnostic role of ultrasonography in small thyroid cancers, 13 cases with thyroid nodule less than 1 cm in histological diameter were referenced to comparetive studies of ultrasonographic, pathological and imaging findings. Moreover the progress of 16 thyroid nodules under 1 cm in diameter detected by ultrrasonography was assessed.In the comparetive studies of each imaging finding, ultrasonography findings were found to be most useful for making the diagnosis, its correct diagnosis rate being was 92.3%.In papillary-prodominant cancers, internal hyper-echoic spots in hypoecoic nodules were observed. In follicular-predominant cancers, internal echoes were found to be relatively high.From observation of the clinical courses, only strict follow-up may serve for suspected cases of benign disease, while surgical treatment should be selected after ultrasonography-guided aspiration biopsy is done for probable cases of malignancy.
