Renal rupture associated with a poorly differentiated follicular thyroid carcinoma metastasizing to the thigh muscle, lung and kidney.

A 76-year-old woman with a history of total thyroidectomy for a thyroid carcinoma at the age of 63 was admitted to our hospital for the treatment of a renal rupture induced by a tumor of about 3 cm in diameter. High levels of blood thyroglobulin (Tg>1,000 ng/ml) led us to suspect a recurrence of thyroid carcinoma. Strong accumulation in whole-body 123I and 201Tl scintigraphy scans after the nephrectomy revealed tumors in the right lung and left thigh muscle measuring 5 cm and 9 cm in diameter, respectively. The tumors of the kidney and thigh muscle were pathologically diagnosed as poorly differentiated follicular thyroid carcinoma, and the lung tumor was also suggested to be a metastasis of the thyroid carcinoma based on the scintigraphy findings. We report this rare case of follicular thyroid carcinoma associated with metastases to the thigh muscle and kidney leading to a rupture 13 years after a total thyroidectomy. Care should be taken to determine whether unknown tumors are thyroid carcinoma metastases.