Complex Thyroglossal Duct Cyst in a young adult: review of a case.

Abstract

Background: Complex thyroglossal duct cyst (CGCT) is a congenital condition that develops from cells remaining in the thyroid gland^1,2 and usually appears after an upper respiratory infection. It makes its debut as a mass of soft consistency in the upper part of the cervical midline closely related to the Hyoid bone^1,3, being the most frequent cause of tumor in this area². Its worldwide incidence is 7%² and its frequency are higher in the first two decades of life^1,3, with no difference between sexes². This clinical case aims to show the importance of a timely diagnosis of CGCT, to prevent the evolution of the case into a malignant neoplasm ^2,3. 

Clinical Presentation: A 27-year-old male patient, University of Chile student, systemically healthy. His reason for consultation was a mass of soft consistency that had appeared approximately one month ago in his neck and hurt when swallowing. On clinical examination, he presented an increment of volume of soft consistency in the area of the submental triangle, associated with the hyoid, along with dysphagia, tenderness to palpation, and superior displacement during swallowing and protrusion of the tongue. Blood tests (T3, T4, TSH), thyroid echotomography, and neck CT were performed. The diagnosis was QCTGC, a purely surgical approach was decided. 

Clinical Relevance: QCTGC is a pathology that occurs mainly in the first two decades of life^1,3 it is the most frequent cause of tumors of the midline of the neck² and can be the differential diagnosis for dermoid cysts, lymphadenopathy, and thyroid cysts; and more rarely with lymphangiomas, hemangiomas, and salivary cysts¹. The literature states that the natural course of the disease is best described as repeated inflammatory episodes and external fistulization^2,3. The approach is purely surgical, and the technique with the best prognosis is the Sistrunk³ Technique. Something to consider is the 1% possibility of generation of a malignant neoplasm^1,2,3. 

Conclusion: Although it is a frequently benign cyst, a correct diagnosis is essential to avoid overtreatment (such as a not indicated surgery) or undertreatment, which could lead to the generation of a malignant neoplasm over time.