Unveiling Follicular Thyroid Carcinoma by Solitary Spinal Metastasis Causing Severe Neurological Deficit in a 67-Year-Old Female

Background: Follicular thyroid carcinoma (FTC) is a differentiated thyroid malignancy that exhibits the ability to metastasize hematogenously to distant organs, including the lungs and bones. Spinal metastasis is an unusual site for metastasis that even when occurs, presents late in the disease course and is often associated with advanced disease and poor prognosis. Until 2019, the literature only showed 29 cases of FTC with spinal metastasis as the first presenting feature. Case Presentation We present a case of a 67-year-old female with no previous history of thyroid malignancy who presented with an acute onset of severe neurological deficit that ended up bedridden. Magnetic resonance imaging (MRI) of the spine revealed a spinal lesion causing severe spinal cord compression. Urgent surgical decompression was performed, and the histopathological analysis confirmed the presence of metastatic FTC. Subsequent comprehensive evaluation, including thyroid ultrasonography and unveiled a very small primary thyroid tumor. Conclusion: This case report highlights the importance of considering FTC as a differential diagnosis in patients presenting with spinal metastasis, even in the absence of known primary thyroid malignancy. Prompt diagnosis, comprehensive staging, and multidisciplinary management are crucial in optimizing treatment outcomes for patients with FTC presenting with spinal metastasis and improvement of prognosis.