Clinical significance of ultrasonographic examination including detection of thyroid gland diseases when surveying cervical lymph nodes in subjects with oral squamous cell carcinoma

Abstract

The objective of this study was to evaluate the clinical significance of ultrasonography (US) for screening for thyroid gland diseases when surveying the cervical lymph nodes to detect metastasis in subjects with oral squamous cell carcinoma (SCC). The detection rates and characteristics of abnormal thyroid findings detected by US in 301 subjects with oral SCC were analyzed. Subjects with abnormal findings were referred to thyroid specialists and the diagnoses and treatments from these specialists were noted. The ratio of subjects who consulted a thyroid specialist after indications of thyroid gland abnormalities to analyze subject compliance was also examined. Follow-up examinations were regularly conducted to assess any changes in the thyroid gland. Of the 301 subjects with oral SCC, 91 had abnormal thyroid gland findings on US. As subject age increased, the rate of detection of abnormal thyroid gland findings on US significantly increased. The rate of detection of abnormal findings in women by US was significantly higher than that in men, but the male-to-female ratio was lower compared with that in previous reports. It was demonstrated that oral SCC in the floor of the mouth was associated with the highest prevalence of abnormal findings in the thyroid gland (40%), followed by oral SCC of the maxillary gingiva (39%). Of the 91 subjects with abnormal findings, 10 showed enlargement in the size of the lesion on follow-up examination with US. Eleven subjects with no abnormal findings on initial examination showed abnormal findings on follow-up examination. The results suggest that subjects with oral SCC have a relatively high rate of abnormal findings in the thyroid gland that can be detected by US. Scans that include the thyroid gland should be performed when surveying cervical lymph nodes for metastasis during US examination. Particular attention should be paid to thyroid gland-related diseases in older men who have oral cancer and to thyroid gland abnormalities if patients had oral SCC in the floor of the mouth or of the maxillary gingiva. It is recommended that follow-up US examinations be regularly performed in cases of oral SCC.