Laboratory Studies
Macroglossia involves numerous etiologic factors, but a carefully considered patient history can indicate the exact cause and thus determine the need for lab tests. [3] For example, if macroglossia is caused by amyloidosis, microscopic examination with Congo red staining may be warranted, showing classic apple-green birefringence under polarized light. Thyroid function tests can also be obtained when hypothyroidism is suspected. Laboratory studies can also be ordered to evaluate for angioedema.
Imaging Studies
Imaging studies in macroglossia include the following:
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Computed tomography (CT) scanning and magnetic resonance imaging (MRI) - Helpful if macroglossia is interfering with the airway, especially in severe obstructive sleep apnea; such studies are also obtained to help delineate the extent of tumors and aid in planning for surgical resection
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Ultrasonography - May be applicable as a primary diagnostic modality to determine the size of a tongue lesion [4]
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Panorex and cephalometric radiographs - Are very helpful in identifying dental or skeletal deformities associated with macroglossia
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Modified barium swallow study - May be helpful in evaluating for baseline dysphagia
Diagnostic Procedures
Diagnostic procedures must be performed according to the suspected etiology of macroglossia. Any physician who has taken a tongue biopsy knows that significant bleeding can occur. Certainly this potential is even greater with vascular or even inflammatory lesions.
Much of the time, especially for base-of-tongue lesions, biopsy can be performed safely only in the operating room, after securing the airway. Performing the biopsy can be perilous because intubation may not be easily completed in patients with obstructing tongue lesions; a controlled environment and the ability to perform tracheotomy are necessary for manipulation of the base of the tongue.
Biopsies of small lesions in the anterior tongue can usually be safely performed in the clinic, but these small lesions are often not responsible for the global enlargement demonstrated in macroglossia.
Fine-needle aspiration (FNA) may not be adequate for diagnosis of difficult-to-reach lesions in the posterior tongue. For example, an FNA alone cannot be used to diagnose lymphomas or other malignancies. Clinical judgment should be used to determine whether FNA can obtain an appropriate amount of tissue for assessment given this significant differential diagnosis.
Histologic Findings
Given the vast differential diagnosis in macroglossia, listing all of the possible histologic findings would be imprudent. However, in Down syndrome and Beckwith-Wiedemann syndrome—although the diagnoses are made via clinical findings—tongue muscles show hypertrophy and hyperplasia.
Staging
There is no specific staging for macroglossia. Clinical and CT-scan examination will determine the size and location of the tongue in the oral cavity.
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Clinical appearance of "true macroglossia."
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Surgical excision of tongue lesion.
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Surgical site after excision of lesion.
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Gross specimen of excised lesion.
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Surgical site sutured.
