Pathological features of follicular thyroid carcinoma with bone metastasis as the f i rst symptom

Objective To evaluate the pathological features of the follicular thyroid carcinoma (FTC) with bone metastasis as the fi rst symptom. Methods Clinical data about 28 patients with FTC admitted to the department of pathology of Chinese PLA General Hospital from April 2008 to April 2014 were retrospectively analyzed, and pathological features were compared between cases with bone metastasis as the fi rst symptom and cases without bone metastasis. Results Of the 28 cases with FTC, there were 9 cases with bone metastasis, and all of them made bone metastasis as the fi rst symptom (32.1%) which occurred in the axial skeleton. In the cases of bone metastasis, the male to female ratio was 1:8 and the average age of the patients was 62.6 years old. In the cases without bone metastasis, the male to female ratio was 1:2.8 and the average age was 52.3 years old. FTC without metastasis might appear eosinophilic degeneration, hyaline degeneration, vascular invasion or even the sarcomatous change, and many other kinds of pathological features. However, FTC with metastasis had only one form. Conclusion FTC is susceptible to bone metastasis. Some patients with FTC have bone metastasis as the fi rst symptom. FTC with bone metastasis has smaller atypia, and it should be excluded if bone destruction is found in clinical.