Overview 

Macroglossia is a condition where the tongue protrudes from the mouth and teeth in a neutral, resting position. It is usually a painless, generalised condition where the gradual enlargement of the tongue is noted. It is associated with difficulties in speech, eating and drinking, and even breathing. 

Macroglossia is considered congenital when it is present since birth. Congenital macroglossia can be isolated, where it is passed down from parent to child, or it can be a feature of a genetically inherited, more complex, medical syndrome.

Identifying and treating macroglossia involves various methods, starting with focusing on finding and addressing the underlying cause.

What is macroglossia?

Macroglossia is a relatively uncommon condition characterised by a large tongue that protrudes beyond the mouth.¹ The condition is also called enlarged tongue or giant tongue. The enlargement of the tongue can be either muscular or vascular in nature.¹

Macroglossia is a digestive system disorder, as the tongue is an organ of the digestive system. It is known to affect more children than adults and is primarily known as a symptom for another condition.

Types of macroglossia

There are two main types of macroglossia primarily seen:

True macroglossia

In this case, the tongue is enlarged due to some underlying reason. 

This can further be classified into the following two types of macroglossia:

Congenital macroglossia

This is when the patient is born with this condition that affects their tongue. Congenital macroglossia has been known to be associated with a number of conditions such as Beckwith-Wiedemann syndrome, Hunter syndrome, Down syndrome, Pompe disease, Robinow syndrome, hemangioma etc.²

However, it is important to note that it is not a necessary to have macroglossia associated with any identifiable underlying associated with it. 

Acquired macroglossia 

Acquired macroglossia occurs when some other underlying condition has caused the development of macroglossia. It can be linked to some other health conditions (like amyloidosis, hypothyroidism, acromegaly), some forms of cancer (like lymphangioma or lymphoma), allergic reaction or infection (diphtheria). Acquired macroglossia can also occur as a result of some surgeries or medical treatments.

Relative macroglossia 

In this case, there is no enlargement of the tongue. The tongue has a normal shape and size, but it appears enlarged in comparison to the other oral cavity structures. This can be observed in conditions such as angioedema, muscular hypotonia etc.

Congenital macroglossia

Congenital macroglossia, as discussed above, occurs when the condition persists in children since birth. 

Causes of congenital macroglossia 

Congenital macroglossia can be genetically associated with a variety of underlying conditions and can be classified into different categories on the basis of its cause.³ These categories are given below:

1. Overgrown tongue tissue 

This refers to the excessive proliferation of cells within the tongue tissue, leading to increased tissue size, and subsequently tongue size. 

It is seen in conditions such as Beckwith-Wiedemann syndrome, congenital hypothyroidism, Hunter syndrome (more commonly known as mucopolysaccharidoses), genetic abnormalities etc.

2. Tissue infiltrate

This is the presence of infiltrates in the form of inflammatory, cancerous, or other abnormal cells like venous and lymphatic cells within the tongue tissue.

It is commonly seen in conditions like neurofibromatosis, neoplasms, and mucopolysaccharidosis among others.

3. Relative macroglossia

As described above, relative macroglossia occurs when the tongue appears larger in size relative to the size of the oral cavity, but there is no actual increase in the size of the tongue tissue. This is often a result of other anatomical or developmental factors.

It can be seen in conditions like micrognathia where the lower jaw is underdeveloped or smaller in size.

4. Infection or inflammation

Macroglossia can result from infectious or inflammatory causes, resulting in an increase in tongue size either due to inflammation or hypertrophy (thickening or enlargement of the cells of the tongue). It is seen in conditions such as diphtheria, tuberculosis etc.

Additionally, isolated congenital macroglossia, which is not associated as part of a broader syndrome or with other genetic abnormalities, can be genetic and passed down from parent to child with a 50% chance if one parent has the condition.

Symptoms of congenital macroglossia

Patients with congenital macroglossia present the following symptoms:

• Protruding tongue
• Drooling
• Difficulty breathing
• Dysphagia - Difficulty eating or drinking
• Poor weight gain in infants
• Difficulty talking
• Frequent tongue injury due to biting
• Snoring
• Stridor - Presence of sharp, high-pitched sounds during breathing
• Malformed teeth or tongue
• Mouth ulcers
• Upper airway obstruction with sleep apnea in severe cases
• Increased risk of upper respiratory tract infection

Diagnosis

Diagnosis of macroglossia can involve one or a combination of the following steps:

1. Physical examination 

Examination of the mouth is done and measurements are taken to compare it to the rest of the mouth. The light is also checked for ulcers, swelling or discolouration. 

2. Medical history

The medical history of the patient will help identify any disease or other condition that might be causing macroglossia. Similarly family history, for as far back as three generations, is also taken to look for any possible underlying conditions.

3. Blood tests

Depending on the findings of the physical examination and medical history, the patient might need to undergo blood tests to check for or even confirm conditions. 

4. Imaging tests

Tests like ultrasounds, MRI or CT scans might also be employed to examine tissues in and around the mouth.

Treatment

Macroglossia’s primary treatment involves the treatment of the underlying condition that is leading to this problem. Furthermore, the choice of treatment for macroglossia involves understanding the various features of the condition like its size, location and form along with the complications it leads to.

The methods commonly employed for the treatment of macroglossia are:

1. Speech therapy

This treatment is used in cases of mild macroglossia and is discussed only in aiding in speech improvement. Here a speech therapist teaches the patient how to control the movement and positioning of the tongue and improve speech. 

2. Medications 

Medications are prescribed when the underlying condition leading to the macroglossia can be treated with medicines. This is seen in conditions like hypothyroidism, tuberculosis, and syphilis.

3. Orthodontic treatment

Macroglossia arises from dental issues, or if it results in conditions associated with the dental region, then orthodontic treatment can help manage or treat this condition.

4. Surgical methods 

While most cases of macroglossia can be managed conservatively, some cases require surgery. The most common surgical treatment of macroglossia is the removal of part of the tongue, referred to as glossectomy. Though less common, it is still observed in around 10% of the cases. For congenital cases of Beckwith-Wiedemann syndrome, glossectomy is observed in 40% of patients.⁴

A multidisciplinary approach is advised for the diagnosis and treatment. This might involve a coordinated approach from physicians, orthodontists, surgeons, radiotherapists, and geneticists over a prolonged time. This results in minimising the risk of permanent speech or physical complications.

Summary

Macroglossia which is characterised by an enlarged tongue protruding from the mouth, can be congenital or acquired. The congenital form of macroglossia can manifest independently as an isolated condition or it can be part of a larger condition or syndrome like in the case of Beckwith-Wiedemann syndrome, Down syndrome, Hunter syndrome (more commonly known as mucopolysaccharidoses) etc. 

Diagnosis of macroglossia involves a physical exam as well as a medical history of the patient and their family. It is also accompanied by blood work and imaging in most cases. Once diagnosed, the condition is treated by primarily treating the underlying condition that has resulted in macroglossia. This is done with medication, therapy, dental treatment and in severe cases surgery called glossectomy. A multifaceted approach is often used to help the patient alleviate challenges in speech, swallowing, breathing and dental or oral issues.