Metastatic Renal Cell Carcinoma Presenting with Thyroid Nodule and Addisonian Crisis: Tumour-To-Tumour Metastasis

Metastasis to the thyroid gland is uncommon. More infrequent is metastasis occurring within a primary thyroid carcinoma. We report a rare case presenting as an enlarging primary thyroid tumour, harbouring metastatic renal cell carcinoma within. The primary thyroid tumour was only identified after thyroidectomy. The pathology of metastatic disease into a thyroid neoplasm is demonstrated with a brief review of the literature.