METASTATIC THYROID-CANCER AS AN INCIDENTAL FINDING DURING NECK DISSECTION - SIGNIFICANCE AND MANAGEMENT

Occult thyroid cancer is an occasional incidental finding during surgery for other indications and is usually considered of minor clinical significance; however, the appropriate approach for incidentally found metastatic thyroid cancer is less clear especially when it occurs in the context of another malignancy that has more aggressive potential. Among 2,855 patients treated for squamous cancer of the tongue at The University of Texas M. D. Anderson Cancer Center, eight patients had coexisting differentiated thyroid cancer metastatic to cervical lymph nodes which was found incidentally during regional lymph node dissection. The eight patients included three women and five men with a median age of 47 years (range, 32-62 years); tumors were of the papillary variety in four patients and follicular in the other four. In one patient, no gross or microscopic primary tumor could be identified after thyroidectomy; in another patient, no gross tumor was evident, but whole organ section revealed an area of fibrosis consistent with a primary lesion. Two patients had primary lesions less than 1 cm in maximal diameter. In four patients who had no surgery, physical exam and radiologic evaluation failed to show any intrathyroidal lesions. Clinically relevant thyroid cancer did not develop in any of those patients during the duration of documented follow-up (1-15 years). Three patients died of progressive tongue cancer, one patient of unrelated pulmonary disease, and four patients remain alive without evidence of disease for 1 to 15 years of available follow-up. We suggest that differentiated thyroid cancer discovered incidentally during surgery for another, potentially more aggressive malignancy may be approached conservatively when the thyroid gland does not demonstrate clinical or radiologic lesions.