Hürthle cell adenoma arising in a thyroglossal duct cyst

Thyroglossal duct cyst: personal experience and literature review

The thyroglossal duct cyst [TDC, or thyroglossal tract remnant (TTR)] is a well recognized developmental abnormality which arises in some 7% of the population. As a consequence, it represents the most common type of developmental cyst encountered in the neck region. It typically presents as a mobile, painless mass in the anterior midline of the neck, usually in close proximity to the hyoid bone. Less often, TDCs may present with signs and symptoms of secondary infection, or with evidence of a fistula. While TDCs are most often diagnosed in the pediatric age group, a substantial minority of patients with TDCs are over 20 years of age at the time of diagnosis. The standard surgical approach to TDC, encompassing removal of the mid-portion of the hyoid bone in continuity with the TDC and excision of a core of tissue between the hyoid bone and the foramen cecum, dates back to the late 19th and early 20th centuries and is often referred to as Sistrunk's operation. Malignancy is rarely encountered in TDCs; when such rare tumors do develop (in the order of 1% or so of patients with TDCs), they usually take the form of either papillary carcinoma of thyroid origin, or squamous carcinoma.

Follicular adenoma in a juxtathyroidal thyroglossal duct cyst with papillary carcinoma in the adjacent thyroid gland

This patient presented with a neck mass diagnosed as a papillary thyroid carcinoma by fine-needle aspiration. Preoperative computed tomography revealed a papillary carcinoma within a juxtathyroidal thyroglossal duct cyst. After surgery, the initial diagnosis was papillary thyroid carcinoma. After correlation with the computed tomography, the diagnosis was revised to a papillary thyroid carcinoma plus a follicular adenoma in a juxtathyroidal thyroglossal duct cyst. This case demonstrates the need for close clinical and radiographic correlation in such a complex case.

Papillary Carcinoma Arising in a Thyroglossal Duct Cyst

The thyroglossal duct cyst (TDC) is a congenital anomaly appearing as an asymmetric midline neck mass. The TDC is the most common cyst in the neck and is thought to originate from epithelial remnants of the thyroglossal tract. 1 Generally the TDC is benign, but about 1% contain a malignant neoplasm. 1,2 About 125 cases of malignant neoplasm arising in the TDC have been reported in the literature. 3–6 We present an additional case of papillary carcinoma arising in a TDC and discuss appropriate management.