Abstract
Objective: Since incidental thyroid tumors are frequently observed in carotid ultrasonography, a clinical standard is required to conduct efficient screening for those who would need further examination. In this study, we analyzed the results of ultrasonographic examinations in order to determine the frequency of incidental thyroid tumors.
Methods: We conducted carotid ultrasonography on all persons who underwent Ningen Dock from April, 2009 to March, 2013 at Koyama Memorial Hospital.
Results: Thyroid tumors were detected in 461 subjects (45.3%). Individual category rates were as follows: category A2 in 302 subjects (65.5%), category B in 155 (33.6%), and category C in 4 subjects (0.9%). Among people in need of further examination (i.e. category B and C subjects), 59 (37.1%) underwent examination as outpatients in our hospital and 16 of them (27.1%) underwent fine needle biopsy. However, no malignancy was observed.
Conclusions: The findings of this study suggest that a high rate of incidental thyroid tumors was observed in carotid ultrasonography (over 45%), but fortunately we have detected no malignancy up to now. Ultrasonography surveys of infants following the Fukushima nuclear disaster suggested that the rate of category A2, B, and C was 48.4%. We consider that the high-performance of the ultrasonography system used to be one of the primary reasons for such a high frequency of incidental thyroid tumors.
