Bone Metastases in Follicular Carcinoma of Thyroid

Though the association between follicular carcinoma and bone metastasis is well established, the site-wise distribution is not known. One hundred seventy-three patients of follicular carcinoma presenting between 2003 and 2011 were selected from 1093 patients of follicular lesions presenting at a single institution. Of these, 59 (34%) with bone metastasis were included in the study. Fifty of the 59 patients (84.7%) had metastasis at presentation, while 9 developed bone metastasis during follow-up. Sixty-one percent had solitary metastasis, 15 (25.4%) had multiple bone involvement, while 8 patients (13.6%) had synchronous lung metastasis. Overall, the spine was the commonest site of bone metastases, seen in 20 patients (33.9%), followed by the pelvis, skull, long bones and sternum. Bone metastasis is a known phenomenon in follicular carcinoma. The spine is the commonest site followed by the pelvis.