Cervical masses as manifestation of papillary thyroid carcinomas ≤10 mm in diameter, in patients with unknown thyroid disease

BACKGROUND Papillary thyroid microcarcinomas are tumors often found accidentally after thyroidectomy for other thyroid disorders. METHODS Patients with enlarged lateral cervical masses, with unknown thyroid disease, found to have metastases from papillary thyroid carcinoma </=10 mm in diameter, were compared to patients operated on for nodular or multinodular goiter, who were incidentally found to have papillary thyroid microcarcinomas. RESULTS Group A included 24 patients with an enlarged lateral cervical mass whereas group B included 30 patients presenting with nodular or multinodular goiter. Patients in both groups underwent surgery. After thyroidectomy and lymph node dissection, pathology revealed multifocal papillary carcinomas of 1-10 mm, with invasion of the thyroid capsule and surrounding soft tissue in most of the cases in group A. Two patients presented with distant metastases at diagnosis which were surgically removed. During follow up, 3 patients (12.5%) presented with new cervical metastases which were surgically removed or treated with additional radioactive iodine. At last follow-up, all patients were alive. In contrast, all patients in group B had unifocal papillary thyroid carcinoma 1-10 mm in maximum diameter, with no infiltration or extension into the adjacent tissue, or cervical lymph node metastases. CONCLUSION Two groups of papillary thyroid microcarcinomas characterized by different clinical and biological behaviours are identified. Significant differences were found between these groups concerning the age, tumor size, number of tumor foci, lymph nodes metastases and extrathyroidal extension of the tumor. Papillary thyroid carcinomas of small (</=10 mm) size may have aggressive behaviour or be metastatic, and this subgroup should be treated and followed up as are other large, differentiated thyroid cancers.