Lingual thyroglossal duct cysts--a review

Objectives

Lingual thyroglossal duct cysts (TGDC) are rare and liable to be missed in a cursory clinical examination. This study aimed to report the details of lingual TGDC from the authors’ series and review existing literature on the entity.

Methods

A 12 year retrospective survey of all cases of thyroglossal duct anomalies managed at a tertiary teaching hospital was conducted to identify those with lingual TGDC. Their clinical presentation, investigations, diagnosis and management were analysed. Case series from anecdotal published English literature were critically reviewed with particular regard to diagnosis and management.

Results

Of 78 cases of thyroglossal duct anomalies, 3 were lingual TGDC. All were females. One neonate presented with feeding difficulty and was clinically misdiagnosed as a ranula. The two older children presented with a cyst at the foramen caecum. The varied imaging and diagnostic dilemma are presented. The older children had cysts abutting the hyoid and were managed with transoral excision and a Sistrunk procedure; the neonate was managed with transoral excision only. This report also reviews the sparse literature and discusses specific issues in their treatment. The differential diagnoses encompass a wide array of developmental and neoplastic entities. Specific anatomic imaging with USG/CT/MRI and functional evaluation with radionuclide thyroid scan are essential investigative modalities. Besides a classical Sistrunk procedure and simple transoral excision, newer less invasive treatment options including marsupialisation and alcohol ablation have been reported.

Conclusions

In conclusion, the diagnosis and management of lingual TGDC needs to be individualised depending on their presentation and anatomic location. The Sistrunk's procedure is ideal for those in close proximity to the hyoid; however complete cyst excision would suffice in the rest.