A Case of a Rare Association Between Right Thyroid Hemiagenesis, Lingual Thyroid, and Papillary Thyroid Cancer

L ingual thyroid and thyroid hemiagenesis are rare thyroid developmental abnormalities. These conditions can be present with other thyroid diseases, whether functional ones involving abnormal thyroid hormone levels, or structural ones such as presence of thyroid nodules, however the association with thyroid cancer and lingual thyroid or thyroid hemiagenesis is rare. In addition to that, when thyroid hemiagenesis is present, it is usually in the left lobe. We describe here a pregnant patient who presented with metastatic cervical nodes from thyroid cancer who was found on imaging to have right thyroid hemiagenesis. After she underwent an initial surgery for thyroid cancer and metastatic nodal disease, she was then later discovered to have a lingual thyroid. In this case we report this extremely rare combination and also discuss the potential implications of this association on the diagnosis and management of these patients particularly initial surgery and imaging studies needed for the thyroid cancer.