Lymphangioma is histologically and etiologically similar to hemangioma, except that the abnormal vessels are filled with a clear protein-rich fluid containing a few cells (lymph) rather than blood.Lymphangiomas may occur alone or (more frequently) in association with hemangiomas or other anomalous blood vessels with which the lymphangiomatous vessels are anastomosed. The tongue is the most common oral location for this lesion. Together with hemangioma, lymphangioma is an important cause of congenital macroglossia.
Lymphangiomas are frequently without a clear anatomic outline and present on clinical examination as soft masses that dissect tissue planes and turn out to be more extensive than anticipated. Large lymphangiomas spreading into and distending the neck are referred to as cystic hygromas.
Differential diagnoses of lymphangiomas of the tongue include hemangioma, congenital hypothyroidism, mongolism, amyloidosis, neurofibromatosis, various storage diseases (eg, Hurler’s syndrome and glycogen storage disease), and primary muscular hypertrophy of the tongue, all of which may cause macroglossia. The differential diagnosis should also consider certain anomalies in the neck, including various inclusion cysts, cellulitis, and plunging ranula, which large angiomas of the neck may simulate. Abnormalities of the mucosa overlying a lymphangioma may give the appearance of a localized glossitis and may draw attention to the presence of a small lesion buried in the tongue. The typical clinical appearance of oral lymphangioma is that of a racemose surface. The problems of managing lymphangiomas are similar to those of managing hemangiomas.
In neonates, localized superficial cysts of the alveolar mucosa with a lymphangiomatous histologic picture are described as alveolar lymphangiomas.Such lesions, which are more common in black neonates than in white neonates and which are probably often misidentified as eruption cysts or mucoceles, disappear spontaneously with chewing and with tooth eruption.