Metastatic papillary thyroid carcinoma presenting as an isolated renal mass: Case report and review of the literature.

Distant metastasis of Papillary Thyroid Cancer (PTC) to the kidney(s), while rare, has been observed, with approximately 30 cases described in the literature. We present the case of a 28-year-old male who was diagnosed with metastatic PTC following resection of a solitary renal mass. Pathological analysis of the thyroid gland following subsequent thyroidectomy revealed positive regional lymph nodes consistent with metastatic PTC, however, no evidence of malignancy was identified in the thyroid gland. To our knowledge, this is the only known case of metastatic PTC involving the kidney in which no primary lesion was found in the thyroid gland.