Metastatic Papillary Thyroid Carcinoma Presenting as Abducens Palsy Complicated by Ocular Neuromyotonia.

Papillary thyroid carcinoma (PTC) is a type of well-differentiated thyroid cancer that accounts for the majority of thyroid malignancies. The prognosis of PTC is very good and distant metastases are rare, especially to the skull base. The authors report the case of a 47-year-old woman with biopsy-proven PTC treated with surgery and radiation therapy who presented with headache and diplopia after 5 years and was found to have clivus and cavernous sinus metastasis. Following radiation therapy for her skull base and cavernous sinus lesion, she subsequently developed sixth nerve ocular neuromyotonia. Possible causes and treatments are reviewed.