Case ReportsMassive Skull Occult Metastasis of Follicular Carcinoma Report of a Rare CaseShimia, Mohamad MD*; Halimi, Monireh MD†; Panahi, Farid MD‡; Dokht Ghafari M., Yazdan MD§ Author Information *Department of Neurosurgery, Imam Reza Teaching Hospital, School of Medicine †Department of Pathology, Alzahra Teaching Hospital, School of Medicine ‡Neurosciences Research Center, School of Medicine §School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran The authors declare no conflict of interest. Reprints: Farid Panahi, MD, Department of Neurological Surgery, Imam Reza Teaching Hospital, School of Medicine, Tabriz University of Medical Science, Golgasht Ave, Tabriz 5166859188, Iran (e-mail: [email protected]). Neurosurgery Quarterly: May 2015 - Volume 25 - Issue 2 - p 165-166 doi: 10.1097/WNQ.0000000000000015 Buy Metrics Abstract Follicular thyroid carcinoma accounts for 15% of thyroid cancer, which occurs more commonly in the elderly women. This type of thyroid cancer is usually characterized by a palpable nodule in thyroid gland, but occult metastasis of follicular thyroid carcinoma is rare and unusual. Herein, we report an 81-year-old woman with a history of palpable small mass at frontal bone with a progressive enlargement and an accelerated growth, with 1 in the last 12 months. At present, true size of tumor is 5.56×9.84 cm in frontal bone. Neuroimaging (computed tomography) of the skull bone demonstrated a lytic metastatic tumor. On the basis of histopathologic examination of the skull mass, diagnosis of metastatic follicular carcinoma was confirmed. Because of rare incidence of metastatic follicular thyroid carcinoma, this case is worth to be considered in detail. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.