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.