99m Tc-Octreotide-Avid Brain Mass In A Patient With Poorly Differentiated Papillary Thyroid Carcinoma, Hope In Despair.

Brain metastases of PTC are rare and occur in 0.1-5% of the patients, especially in the poorly differentiated types that usually fail to concentrate iodine. We present a rare case of PTC with probable brain metastasis in a 58-year-old woman with a history of poorly differentiated PTC that showed elevated Tg levels and no metastasis was detected in the whole-body iodine scan, despite the positive 99m Tc-octreotide scintigraphy. This imaging modality could be helpful as a diagnostic guide for radionuclide therapy with labeled somatostatin analogs in cases of thyroid carcinoma with elevated Tg levels and negative whole-body iodine scan.