A Rare Case of Thyroglossal Duct Cyst Cancer and Literature Review.

Thyroglossal duct cyst is the most common thyroid developmental abnormality with a prevalence of 7%, but thyroglossal duct cyst cancer is rare. The incidence of thyroglossal duct cyst cancer is about 1%. The diagnosis is limited by low yield on fine-needle aspiration biopsy (FNAB), and most cases are diagnosed after surgery. There is a paucity of data on the utility of thyroglobulin washout for diagnosis of thyroglossal duct cyst cancer, and it has not been mentioned in previous case reports/series. Papillary thyroid cancer is the most common pathology. Preoperative planning is important as the decision about total thyroidectomy with the Sistrunk procedure (excision of the thyroglossal duct cyst, middle part of hyoid bone, and surrounding tissue around the thyroglossal tract) depends on the presence of clinical or radiological thyroid abnormality. Thyroglossal duct cyst cancer has an excellent prognosis. However, owing to a lack of standard of care for this type of thyroid cancer, there is institutional variability in management. We present a case of thyroglossal duct cyst cancer in a man presenting with painless midline neck swelling. Imaging was suspicious for thyroglossal duct cyst cancer. FNAB was benign. The patient underwent the Sistrunk procedure and pathology was positive for papillary thyroid cancer.

Upper neck papillary thyroid cancer (UPTC): A new proposed term for the composite of thyroglossal duct cyst-associated papillary thyroid cancer, pyramidal lobe papillary thyroid cancer, and Delphian node papillary thyroid cancer metastasis.

OBJECTIVES/HYPOTHESIS: Thyroglossal duct cyst (TGDC) is a common congenital anomaly, but TGDC carcinoma is rare. Thyroglossal duct cyst carcinoma management is controversial, especially that of the orthotopic thyroid gland. We aim to provide an insight into the pathologic basis of this management controversy through the review of 28 TGDC cancer cases, thus far the largest such series to our knowledge. STUDY DESIGN: Retrospective. METHODS: Twenty-eight cases recorded as TGDC cancer in the hospital database were reviewed; their initial clinical diagnosis from medical chart review (DX1) and final pathological review diagnosis (DX2) through pathology slides review by our pathologist (blinded to DX1) were compared. The thyroid gland management and pathology were evaluated. RESULTS: In the 28 TGDC carcinoma (hospital-recorded diagnosis) patients, DX1 and DX2 were respectively reported as 53% and 14% TGDC carcinoma, 11% and 29% as pyramidal lobe primary, and 4% and 25% as metastatic Delphian node. Thirty-two percent of cases were in the indeterminate category, in both DX1 and DX2, but included different patients. Thyroidectomy was performed in 54% of the cases, papillary thyroid cancer (PTC) was reported in 37% of these thyroid glands. Concurrent thyroid gland malignancy was reported in all Delphian node and pyramidal lobe PTC patients. CONCLUSION: The diagnosis of TGDC cancer comprises a heterogeneous group that includes true TGDC cancer, pyramidal lobe primary, Delphian node metastasis, and indeterminate cases. We propose a new terminology of upper neck papillary thyroid carcinoma (UPTC) to denote this heterogeneous group and recommend a rational algorithm for management. Correct pathologic subcategory and thyroid ultrasonography are essential for optimal management of thyroid gland in UPTC cases. LEVEL OF EVIDENCE: 4. Laryngoscope, 126:1709-1714, 2016.

Cáncer de quiste en conducto tirogloso / Thyroglossal duct cyst cancer

El quiste del conducto tirogloso es una de las anomalías del desarrollo que se presenta más frecuentemente en el cuello. La presencia en este de carcinoma aislado o concomitante con cáncer en tiroides, es muy infrecuente. Se expone aquí el caso de una paciente joven que se presentó con esta entidad. Se describe su presentación y manejo. Actualmente sigue su control en el Servicio de Endocrinología del Hospital San Vicente de Paúl, Heredia, Costa Rica...