Persistent thyroglossal duct

Persistent thyroglossal duct is a congenital anomaly that occurs due to the incomplete obliteration of the thyroglossal duct during embryonic development. This condition is characterized by the presence of a duct that connects the thyroid gland to the tongue base, which normally disappears by the 10th week of gestation.

Etiology

The exact cause of persistent thyroglossal duct is unknown. However, it is believed to be associated with genetic factors and environmental influences during pregnancy. The thyroglossal duct is formed during the descent of the thyroid gland from the base of the tongue to its final position in the neck. If this duct fails to obliterate, it results in a persistent thyroglossal duct.

Clinical Presentation

Patients with a persistent thyroglossal duct often present with a midline neck mass that moves with swallowing or protrusion of the tongue. This is due to the connection of the duct to the tongue. Other symptoms may include discomfort in the neck, difficulty swallowing (dysphagia), and recurrent infections.

Diagnosis

Diagnosis of a persistent thyroglossal duct is often made clinically, based on the patient's symptoms and physical examination. Imaging studies such as ultrasound, computed tomography (CT) scan, and magnetic resonance imaging (MRI) can be used to confirm the diagnosis and rule out other conditions. A fine-needle aspiration (FNA) biopsy may also be performed to examine the cells in the duct.

Treatment

The primary treatment for a persistent thyroglossal duct is surgical removal of the duct and any associated cysts, a procedure known as Sistrunk procedure. This procedure involves the removal of the mid-portion of the hyoid bone along with the duct, reducing the risk of recurrence. Antibiotics may be prescribed to treat any associated infections.

Prognosis

The prognosis for individuals with a persistent thyroglossal duct is generally good, especially when the condition is diagnosed and treated early. However, there is a risk of recurrence if the entire duct is not removed during surgery.

See Also

• Thyroglossal duct cyst
• Congenital anomalies of the neck
• Sistrunk procedure

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