Internist's tumour into thyroid: A case report.

Renal cell carcinoma (RCC) is well known for its unpredictable and diverse behaviour, with tendency to cause synchronous or metachronous metastasis to unusual site, which is why it is called the "internist's tumour."Although thyroid gland is an infrequent site for metastasis of different primary malignancies, metastatic RCC is one of the most common secondary thyroid malignancies. Diagnosis relies on a high index of suspicion in patients with prior RCC, combined with cross-sectional imaging and biopsy. A case of secondary thyroid neoplasm from RCC after 13 years of radical nephrectomy is described with clinicopathological features and literature review.