Metastatic papillary cancer of the neck: a diagnostic dilemma.

The finding of papillary carcinoma in a neck mass usually leads to the presumptive diagnosis of metastatic thyroid carcinoma, with total thyroidectomy revealing the primary tumor. We report five cases of metastatic papillary carcinoma of the neck. The primary tumor in three of the cases was found to be nonthyroidal; two being discovered only after thyroidectomy failed to reveal a primary cancer. In the two thyroidal neoplasms, pathologic examination of the thyroid demonstrated only minimal tumor in one case and no detectable tumor in the other. These cases illustrate the pitfalls of diagnosis and treatment of these tumors and the utility of antithyroglobulin immunostaining in such cases.