Macroglossia

A wide variety of conditions, both congenital and acquired, can cause macroglossia. Congenital macroglossia can be seen in children with Beckwith-Wiedemann syndrome: a pediatric overgrowth syndrome characterized by small head size, enlarged internal organs, and hemihyperplasia (i.e., where structures on one side of the body are larger than the other side). Other causes of congenital macroglossia include glycogen storage disorders, like Pompe disease or mucopolysaccharidoses, a group of conditions that lead to an accumulation of metabolic products in various tissues of the body. 

Common causes of acquired macroglossia include hypothyroidism (e.g., low thyroid hormone levels), diabetes mellitus, and amyloidosis (an inflammatory disease that results in the accumulation of abnormal protein deposits). Blood vessel tumors called hemangiomas and lymphatic or venous malformations may also result in enlargement of the tongue. Other causes of acquired macroglossia include inflammation resulting from radiotherapy, head and neck injuries, and tumors.

In severe allergic reactions, macroglossia may appear due to widespread swelling. Although rare, macroglossia can also be seen as a complication of neurosurgical procedures where a person has been sitting with their neck flexed for a long time. This forced flexed position along with local compression of the tongue by an endotracheal tube can result in decreased venous and lymphatic drainage, resulting in swelling of the tongue. Finally, macroglossia can be a side effect of medications, such as antiretrovirals used in the treatment of HIV infection (e.g., ritonavir, lopinavir). 

Macroglossia is defined as an unusually large tongue that protrudes beyond the dental arch. In some cases, macroglossia can result in orthodontic problems such as dental spacing, an open bite, and malocclusion of the teeth. Individuals with macroglossia may also have a tendency to keep their mouth open to help with breathing, resulting in mucosal drying and, subsequently, more frequent upper respiratory tract infections. 

Diagnosis of macroglossia is usually made based on the inspection of the tongue. A classic test to confirm macroglossia involves assessing the individual’s ability to reach their chin or nose with the tongue. Additionally, imaging studies such as a lateral X-ray view of the skull or magnetic resonance imaging (MRI) can be done to determine the size of the tongue. 

Further diagnostic tests are generally aimed at identifying the underlying cause of macroglossia. Depending on the clinical suspicion, additional tests may involve laboratory tests, genetic studies, and imaging techniques (e.g., abdominal ultrasound or CT scan). Functional tests may also be conducted to identify alterations in speech, chewing, or airway permeability. For example, a polysomnogram may be conducted to rule out sleep apnea, and dysphagia tests may be used to determine the risk of swallowing problems. Finally, in cases where the cause of macroglossia is unclear, a biopsy of the tongue may be performed to rule out conditions like amyloidosis, tumors, or lymphoma. 

Treatment of macroglossia depends on the underlying cause. In cases where macroglossia is a result of a congenital disorder, treatment generally involves orthodontic treatment and speech therapy to adapt the position of the tongue during its different functions. Surgery may be recommended in cases where macroglossia interferes with breathing or causes feeding problems. The most common surgical technique for macroglossia performed by maxillofacial surgeons is a partial glossectomy, which involves a tongue reduction.