Thyroglossal Cyst

ESSENTIAL FEATURES
• Thyroid develops from an evagination of the floor of the primitive pharynx (during fourth week of gestation)
• Abnormal movement of the thyroid anlage can lead to a lingual thyroid or appear as a mass anywhere in the neck midline
• Persistence of the thyroglossal duct leaves an epithelial lined tract that forms a cyst that communicates with the foramen cecum at the base of the tongue
• Tract of a persistent thyroglossal duct extends through the hyoid bone


CLINICAL FINDINGS


SYMPTOMS AND SIGNS
• Lingual thyroid (dysphagia, dysphonia, dyspnea, hemorrhage, pain)
• Rounded, cystic mass in the midline of the neck (just below hyoid bone)
• Cephalad-caudad movement of mass with deglutition and protrusion of tongue
IMAGING FINDINGS
• Lingual thyroid imaged by technetium pertechnetate or radioiodine scintigraphy

DIAGNOSTIC CONSIDERATIONS
RULE OUT
• Dermoid cyst
• Enlarged lymph nodes (especially Delphian)
WORK-UP
• Physical exam
• Cervical ultrasound
• Thyroid scintigraphy
TREATMENT AND MANAGEMENT
SURGERY
• Lingual or ectopic thyroid should be excised
• Acute thyroglossal tract infections should be treated with heat, antibiotics, and incision and drainage (if indicated)
–Complete tract excision (en bloc with middle of hyoid bone–-Sistrunk procedure) once inflammation has subsided
Complications omplications
• Thyroglossal cysts are prone to infection
• Excision of lingual or ectopic thyroid can lead to permanent hypothyroidism
• Carcinoma develops more frequently in ectopic thyroid tissue than normal thyroid tissue
Prognosis
• Recurrence of thyroglossal cyst is 6–9% and is more common following infection


REFERENCES
• De Felice M, Di Lauro R: Thyroid development and its disorders: genetics and molecular mechanisms. Endocr Rev 2004;25:722.