Isolated porta hepatis metastasis of papillary thyroid cancer.

Metastases from differentiated thyroid cancer are usually seen in the cervical or mediastinal lymph nodes, lung or bone. We report a case of papillary thyroid cancer metastasizing to lymph nodes in the porta hepatis. No other site of metastasis was apparent on neck or abdominal exploration or on iodine whole-body scans. The primary tumor was a multifocal papillary thyroid cancer arising on a background of multinodular goiter. The metastasis was observed on a diagnostic radioiodine scan after surgical resection of the primary tumor despite significant (11%) radioiodine uptake by residual thyroid tissue in the neck and was proven by histologic examination and thyroglobulin immunohistochemistry. Although rare, metastasis to porta hepatis lymph nodes should be considered in the differential diagnosis of abdominal radioiodine uptake in patients with differentiated thyroid cancer.