Usually differentiated thyroid cancer has a good prognosis and only rarely shows distant metastasis at diagnosis above all the papillary carcinoma. We present the case of a female patient of 66 years old affected by a papillary thyroid carcinoma with a bone metastasis as initial presenting symptom; she was hospitalized for pelvic pain and motor weakness and treated for severe osteoporosis. The patient was submitted to pelvis X-Ray that showed an area of bone loss and cortical irregularities of the right acetabulum, which was compatible with secondary neoplastic lesion but no primary tumor was found. The bone biopsy showed “papillary thyroid carcinoma, follicular variant”, so the patient was candidated to a total thyroidectomy.