Papillary thyroid microcarcinomas revealed by cervical metastases

Abstract

Papillary microcarcinomas (PMCs) which are 1.0 cm or less in diameter are a specific subgroup of thyroid cancer. As the prevalence of these tumors found in autopsy cases was reported to be 10 to 28.4% in Japan, the necessity of surgical treatment of PMCs has been questioned. However, PMCs are often found in conjunction with advanced metastases in cervical lymph nodes, lung, etc.. We reviewed eight cases with PMCs revealed by the presence of cervical metastases over the past 10 years. Five cases were revealed by manifest cervical lymph node metastases. Two of the other three cases were operated on for treatment of metastatic lesions subsequent to other diagnoses, notably a parotid tumor and lateral cervical cyst. The PMCs were revealed in a postoperative histological study of these two cases. The remaining case was discovered incidentally during neck dissection for laryngeal cancer. Preoperative ultrasonography was undertaken in seven cases. Two cases showed multifocal small high echoic spots without tumors and one case showed no abnormal findings in the thyroid. In all cases, total thyroidectomy, unilateral or bilateral neck dissection and postoperative radioiodine scintigraphy were performed. Multifocal tumors in the thyroid were proven histologically in four cases. In one case, the primary lesion was not found even in a postoperative histological study. In accordance with these observations, PMCs revealed by cervical metastases shoul be treated as advanced thyroid carcinomas.