A Rare Case of Papillary Thyroid Carcinoma in the Thyroglossal Duct Cyst of a 14-Year-Old Female Patient With Left Thyroid Hemiagenesis

Abstract

Congenital abnormalities in the development of the thyroglossal duct are a common pathology in the pediatric population. The exact frequency of hemiagenesis of the thyroid gland is not known because the condition is rarely manifested clinically and is almost always discovered incidentally. Papillary carcinoma of thyroglossal cysts is relatively uncommon, has a good prognosis if promptly detected and treated and occurs mainly in adults. The case we present here is an extremely rare occurrence: a patient with papillary thyroid carcinoma of the thyroglossal duct cyst and thyroglossal duct cyst carcinoma (TDCa). So far, only two such adult patients (women aged 24 and 35) have been described in the world medical literature. The patient we present is a 14-year-old female and is the first described adolescent with papillary carcinoma of the thyroglossal duct cyst and thyroid hemiagenesis (THA). The disease didn't have any clinical manifestations, and the patient was brought in by her parents to improve her aesthetic appearance. Neither the physical examination nor the radiological evaluation showed any signs of malignancy. The diagnosis was reached by our team only after the patoanatomical examination. In this patient's case, due to its early diagnosis, the spread of the disease was limited only to the borders of the thyroglossal duct cyst and the absence of regional and distant metastasis. Surgical removal led to a complete cure, without any postoperative data suggestive of residual disease. The functions of the thyroid gland in her case were not affected, despite her left-lobe agenesis, to which there are multiple proofs, namely the normal blood concentration of the examined thyroid markers: free triiodothyronine (FT3), free thyroxine (FT4), thyroglobulin (TG), thyroid stimulating hormone (TSH), anti-TG (thyroid antibody test (TAT)), anti-thyroid peroxidase (TPO) (microsomal antibody test (MAT)), and normal physical and psychological development.

Keywords: cancer in children; congenital anomalies; head and neck surgery; malignant cyst; maxillofacial surgery; median neck cyst; neck cancer; neck pathology; pediatric surgery; thyroid gland.

Figure 1. An ultrasound image of the neck in the area of the pathological finding reveals the presence of a multiseptated cyst measuring 48 mm in diameter, containing several smaller cysts filled with fluid

Figure 2. Axial view of the CT (with intravenous contrast) head and neck shows a complex cyst with a three-chambered structure (red arrow)

Figure 3. Coronal view of the CT (with intravenous contrast) head and neck shows a complex cyst with a three-chambered structure (red arrow)

Figure 4. Coronal view of the CT (with intravenous contrast) head and neck shows the absence of the left lobe in the thyroid gland and an enlarged right lobe (red arrow)

Figure 5. Photomicrograph of the thyroglossal duct cyst, lined by squamous epithelium with subtotal denudation (arrowhead). The cyst wall harbors thyroid-type papillary carcinoma (arrow); H&E x4.

H&E: Hematoxylin and eosin

Figure 6. Neoplastic papillae are lined by thyrocytes exhibiting nuclear enlargement and overlapping, chromatin clearing (arrowhead), nuclear grooves, and pseudoinclusions (black arrow). Calcifications are evident on the right (outlined arrow); H&E x40.

H&E: Hematoxylin and eosin