Bone metastases without primary tumor: A well-differentiated follicular thyroid carcinoma case.

Metastases to the bone are the most common malignant bone tumors. Prostate, breast, and lung carcinomas are the most common primaries of bone metastases. Bone metastases show poor prognosis in means of median survival; however, some patients with highly curable tumors such as thyroid carcinoma may benefit from treatment. We report and discuss a unique case of a 70-year-old female patient presenting with arm pain, diagnosed with metastatic well-differentiated follicular carcinoma without a primary tumor in the thyroid.