A Uniquely Challenging Case of Poorly Controlled Hyperthyroidism With a Coexisting Thyroglossal Cyst

Hyperthyroidism is a common disease. Thyroglossal duct cysts are also a very common type of congenital anomalies. Their co-existence is, however, rare with only a few cases described in the literature of the same. We describe the case of a 44-year-old female who presented initially 16 years ago with hyperthyroid symptoms related to Graves' disease diagnosed serologically and by thyroid scan and ultrasound. Incidentally, she was also noted to have a non-complicated thyroglossal duct cyst. She was initially started on anti-thyroid medications but remained in a hyperthyroid state throughout most of her illness. Radioiodine ablative therapy and surgical resection were delayed due to the patient's dispreference. After a long period of missed follow up, she presented with a thyroid storm and underwent a total thyroidectomy and cyst resection. The key endocrine issues learned from this case include: 1) dealing with non-compliant patients in terms of poorly controlled hyperthyroidism and refusal to follow the recommended treatment, 2) observing the natural disease progression of untreated Graves' disease coexisting with a thyroglossal duct cyst, and 3) describing a rare incidental finding of a thyroglossal duct cyst coexisting with Graves' disease in the absence of ectopic hormone production. A few cases have described hyperthyroidism related to remnants of thyroid tissue in the thyroglossal duct or related to the thyroid gland. To the best of our knowledge, there are no cases reported of Graves' disease coexisting with a non-complicated thyroglossal duct cyst making our case unique and first of its kind.