Extensive bone metastases as the initial symptom of papillary thyroid microcarcinoma: A case report.

A 53-year-old female patient presented with lumbar and pelvic pain. The 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography scintigraphy showed extensive bone destruction with hypermetabolic osteolysis, with increased 18F-FDG uptake. The histological examination of the pubic bone lesion revealed a metastatic tumor. Neither chemotherapy nor radiotherapy could control the condition. More than a year later, the patient underwent a total thyroidectomy with cervical lymph node clearance. The histological examination revealed a papillary thyroid microcarcinoma (PTMC) in the left lobe with capsular invasion. 131I treatment with thyroid hormone withdrawal followed. The 131I whole-body scintigraphy showed extensive uptake in the basic thyroid deposits, most bones and both lungs. Three months after the 131I treatment, the patient succumbed to cachexia. The present case indicated that not all PTMCs have excellent prognosis and that, despite being rare, clinically significant metastases can arise from a PTMC.