Unusual Papillary Thyroid Cancer Metastases to Kidney and Pharynx: A Case Report

ABSTRACT Objective: The objective of this study is to report a very unusual case of papillary thyroid cancer with metastases to kidney and hematogenous spread to the pharynx. Methods: We reviewed all clinical data available for this patient, including computed tomography (CT) images and pathology samples. A literature search for kidney and pharynx metastases was performed in MEDLINE, using the terms “kidney metastases,” “pharynx metastases,” and “thyroid cancer.” Relevant references were selected and reviewed. Results: A 50-year-old Hispanic woman with a history of papillary thyroid carcinoma (PTC), a total thyroidectomy, plus a modified radical neck dissection, who was treated on 2 separate occasions with 131I (initially 100 mCi, and 1 year later 200 mCi), persisted with elevated thyroglobulin levels. An abdominal CT scan revealed a 3-cm lesion in the left kidney with no metastases to the lungs, bone, or liver. A left nephrectomy was performed. The pathology report confirmed metastases from PTC. Even then, thyroglobulin levels remained elevated. One year later, a CT scan was performed due to a chronic sinus infection, and it showed a mass in the right pharynx region. Fine-needle aspiration biopsy of this lesion reported metastases from PTC. Conclusion: PTC usually has a very indolent behavior. When metastasis is present it normally involves cervical nodes, lungs, or bone. In the medical literature, there are very few case reports of PTC metastases to kidney, such as in our case. To our knowledge, this is the first case report with kidney and pharynx involvement from a PTC. Abbreviations: CT = computed tomography DTC = differentiated thyroid carcinoma FTC = follicular thyroid carcinoma NIS = sodium/iodide symporter PTC = papillary thyroid carcinoma Tg = thyroglobulin TSH = thyrotropin