Occult Follicular Carcinoma of Thyroid Presenting as Skull Bone Metastasis: A Rare Case Report

Abstract

Follicular thyroid carcinoma (FTC) is a well-differentiated tumor and second most common cancer of the thyroid after papillary carcinoma. They account for 5 to 15% of primary thyroid cancers. Most patient present with a thyroid swelling, only up to 11% patient present with distant metastasis. Skull is a rare site for metastasis. The incidence of skull metastasis of FTC is about 2.5% and, in most cases, metastasis occurred after the diagnosis and treatment of primary tumor; but in few cases, skull metastasis was the first presentation of an occult FTC. We report a case of a 63-year-old female presenting with a headache for 6 months and swelling in right parietal vertex region for 1 month. Neuroimaging showed calvarium based intradiploic extradural lytic expansile lesion, which on histopathology showed the features of metastatic follicular carcinoma from thyroid, which was confirmed by Immunohistochemistry (TTF-1). Thyroid examination and thyroid function tests were normal. Subsequent workup revealed an occult primary follicular carcinoma in the thyroid.

Keywords: Skull metastasis, occult primary, follicular thyroid carcinoma (FTC), TTF-1

Cite this Article

Pramila Choudhary, S.R. Negi, Meeta Deval et al. Occult Follicular Carcinoma of Thyroid Presenting as Skull Bone Metastasis: A Rare Case Report. Research & Reviews: Journal of Oncology and Hematology. 2018; 7(3): 30–33p.