Endocrine Abstracts

Introduction: The prevalence of brain metastasis from differentiated thyroid carcinoma is 1%. Brain metastasis as the first manifestation of the disease is extremely uncommon.

Case report: We present a case of 44-year-old woman with headache and a tumor in right parietal zone. The patient has had multinodular goiter for 15 years, with two dominant nodules in left thyroid lobe. Both of them were isoechoic with hypoechoic halo and measured 2 cm. Fine-needle aspiration was benign and without changes over time. Computed tomography scan (CT) and magnetic resonance (MR) brain demonstrated a 6.2×6.5×5 cm right parietal lesion with bone erosion (intracranial and extracranial component) mimicking a meningioma. Laboratory tests were as followed: TSH 1.83 mcU/ml [0.3–5], T4L 0.94 ng/dl [0.9–2.1], thyroglobulin 3207 ng/ml [0–80] and antithyroid antibodies were negative.

Surgery of brain tumor was performed and histopathology revealed a 6×5.7×2 cm dural metastasis and a 4×2.8 cm skull metastasis of follicular thyroid carcinoma. Later, total thyroidectomy detected a 2 cm well differentiated follicular thyroid carcinoma in left thyroid lobe, with a small capsular infiltration and without vascular and lymph node invasion.

After that, radiotherapy and radioactive iodine therapy was administered to the patient with an initial good response.

Conclusions: Brain metastasis from differentiated thyroid carcinoma are rare and dural metastasis from follicular thyroid carcinoma are exceptional, with only a few published cases in the literature. In these cases the prognosis is poor, with a one year survival rate. Although, the treatment is controversial, nowadays brain surgery and radiotherapy are the best options.