A Case of Follicular Variant of Papillary Thyroid Microcarcinoma Presented with Multiple Bone Metastases

Abstract

A 53-year-old man was referred to our hospital with the chief complaint of pain in the right femur. Computed tomography (CT) showed a nodular lesion about 6 cm in diameter located in the left thyroid lobe, and osteolytic change in the second thoracic vertebra and the right femur. Fine needle cytology of the nodular lesion in the left thyroid lobe revealed no atypical thyroid cells. The right femur was broken, and an operation was performed and bone metastasis of thyroid carcinoma was diagnosed based on a bone biopsy. Local radiotherapy was performed for the metastases first, and then the patient underwent total thyroidectomy and D1 lymph node dissection. Follicular variant of papillary thyroid microcarcinoma with multiple bone metastases was conclusively diagnosed. One year after the operation, the treatment with bisphosphonate zoledronic acid at a dosage of 4 mg administered once every 4 weeks was performed, and the administration of I-131 was given twice. Multimodal treatment for multiple bone metastases have been demonstrated to provide improvement in activities of daily life (ADL) and QOL of patients.