Synchronous carcinoma of thyroglossal duct cyst and native thyroid gland

Abstract

The unobliterated portion of embryological thyroglossal duct may present as cystic swelling later in life and may contain functional thyroid follicles. This cyst requires excision along with the entire thyroglossal duct remnant and adjacent portion of hyoid bone. At times, the excised specimen could demonstrate a focus of carcinomatous change inside the cyst wall. Very rarely, this thyroglossal duct cyst carcinoma could be associated with malignancy of native thyroid gland. This case report illustrates an interesting case of synchronous carcinoma of thyroglossal duct cyst and native thyroid gland. It also sheds light on the controversies related to the pathophysiology of such association and the dilemmas surrounding the management of thyroglossal duct cyst carcinoma, with or without concurrent carcinoma of thyroid gland.

Keywords: Ear, nose and throat/otolaryngology; Endocrine cancer; General surgery; Head and neck surgery; Thyroid disease.

Figure 1

Photomicrographs (all H&E staining) of surgical specimen, showing normal thyroid follicles (black arrows) inside the excised thyroglossal cyst (blue arrow) (A) (magnification 10×); papillary carcinoma (black arrow) arising from the thyroglossal duct cyst wall (blue arrow) along with psammomatous calcification (B) (magnification 10×); nuclear features of papillary carcinoma -pseudonuclear inclusions (black arrow), intranuclear groove (blue arrow) with crowding and overlapping of nucleus (C) (magnification 40×); and papillary microcarcinoma (black arrow) in the thyroidectomy specimen (D) (magnification 10×).

Figure 2

Immediate post-therapy scan (50 mCi iodine-131) showing multifocal residue at the thyroid bed (A); and follow-up iodine-131 whole body scan (2 mCi) done after 5 months of radioiodine ablation showed no significant uptake in the thyroid bed or elsewhere in the body (B).

Figure 3

Flow chart depicting the therapeutic approach in thyroglossal duct cyst carcinoma.