Intramedullary Spinal Cord Metastasis as the Presenting Feature of Papillary Thyroid Carcinoma

ABSTRACT Objective The objective of this report is to present an unusual case of intramedullary spinal cord metastasis (ISCM) as the presenting feature of papillary thyroid carcinoma (PTC). Methods The presented case includes clinical, biochemical, and imaging findings as well as surgical and pathology reports. Treatment with radioactive iodine (RAI) and the response to this treatment are presented. Results A 71-year-old woman was evaluated for debilitating low back pain and walking disability. Magnetic resonance imaging demonstrated an oval, lumbar, intramedullary mass with benign features and surgery was scheduled. On preoperative evaluation for the lumbar mass, a multinodular thyroid goiter (unfortunately overlooked previously) was noticed, causing severe narrowing of the trachea. Total thyroidectomy was performed with a pathology diagnosis of PTC. In a second operation, the lumbar lesion was removed and proved to represent metastatic PTC. External beam radiation was subsequently administered to the thyroid bed, lumbar spine, and other skeletal metastases, followed by 150 milliCurie of RAI. A post-treatment scan showed high uptake over the lumbar spine, and skeletal and lung lesions. Clinically, the patient restored her walking ability and back pain improved. Conclusion ISCM rarely is the presenting feature of PTC. Our patient presented with back pain which is the typical, though non-specific symptom, of ISCM. She showed good clinical response to multimodal treatment which is in line with the few other differentiated thyroid cancer patients with ISCM reported in the literature. Prompt surgical resection, followed by external beam radiation and RAI, may improve neurological signs, alleviate pain, and improve quality of life.