Facial nerve palsy from temporal bone metastasis in papillary carcinoma of thyroid: A case report

The most prevalent thyroid cancer, known as papillary thyroid carcinoma, mainly affects those under 45 years of age, which is capable of metastasizing. It is more common for bone metastases to develop in the long bones, ilium, sternum, and scapula. Skull metastasis is common in lung, prostate, and breast carcinomas and, on the other hand, rare for thyroid carcinomas. Temporal bone as a site of metastasis is usually asymptomatic and uncommon. Isolated facial nerve palsy resulting from temporal bone metastasis is another rare phenomenon. Metastatic papillary thyroid carcinoma may have unusual manifestations, such as spinal cord compression due to bone metastases and palsy of the seventh cranial nerve. A 35-year-old female patient presented to the emergency department with gradual onset left-sided facial palsy, known to have a goiter. Nevertheless, she did not seek consultation until after experiencing left-sided facial weakness. On leading questions, the patient complained of weakness around the left eye, weakness around the angle of the mouth on the left side, left-sided earache, and hearing loss. The patient also complained of dysphagia, difficulty in breathing associated with excessive sweating, and a history of significant weight loss.Her CT neck and Neurological imaging were done, suggesting a solid lesion in the right lobe of the thyroid gland and a mass causing lysis of the left temporal bone and involvement of the facial nerve, respectively. A thyroid gland biopsy was taken and was suggestive of papillary thyroid carcinoma. It was later determined that the temporal mass was a metastatic papillary thyroid carcinoma follicular variant, which was eventually excised. In conclusion any patient presenting with isolated facial palsy with known case of thyroid disorder should be evaluated for malignancy as early diagnosis and treatment will limit the progression of the disease.