An 11-year-old girl presents to the clinic with a lesion under the tongue of 3 weeks' duration. She complains of a "mass sensation" while eating and speaking but has no difficulty with swallowing.
DIAGNOSIS: Mucocele of the tongue
Mucoceles are cystic lesions that may occur on the mucosal surfaces of the oral cavity where underlying accessory salivary glands are normally present. The most common location is the lower lip and, less frequently, the floor of mouth, buccal mucosa, and upper lip.1 Mucoceles of the tongue are unusual, constituting only a small percentage of all reported oral mucoceles. In one large series spanning 15 years, only 36 cases of oral mucoceles were reported, of which only 3 were on tongue.2
The mucocele mass is remarkably variable, ranging from just a few millimeters to as large as 20 mm in diameter;3 the surface appearance varies according to size and depth of the lesions. The lesion is usually a round, nontender mass, appearing and palpably cyst-like. In the course of the mucocele development, the size may decrease or increase.4 Mucoceles when superficial could rupture easily and even involute spontaneously. Females are predominantly affected.
The human tongue contains 3 groups of minor salivary glands: glands of Weber along the border of lateral tongue, the glands of von Ebner surrounding the circumvallated papillae, and glands of Blandin and Nuhn embedded within the musculature of the anterior tongue ventrum. The glands of Blandin and Nuhn are mixed mucus and serous salivary glands and extend laterally and posteriorly from the midline, forming a mass resembling a horseshoe with its opening pointing toward the root of the tongue.1
There are 2 reported types of mucoceles: extravasation and retention mucoceles.3 Extravasation mucoceles are formed by leakage of mucus into connective tissues and are usually caused by trauma such as accidental biting or surgery. Inflammatory and tissue repair response occurs, with subsequent formation of a granulation tissue wall. Most of the mucoceles of the tongue involve the salivary glands of Blandin-Nuhn and are of the extravasation type. Vascular and granulation tissue elements may be pronounced. Retention mucoceles occur from obstruction of the salivary gland ducts because of inspissated debris or calculi or from kinking of a tortuous duct, resulting in dilatation. These lesions are also termed salivary duct cysts and are more common in older people compared to the extravasation type.3,5
Extravasation mucoceles seen in children may be difficult to distinguish visually from vascular lesions, pyogenic granuloma, polyps, or squamous cell papillomas.1
Retention mucocele, especially in older patients, must be distinguished from neoplasms of minor salivary gland origin such as mucoepidermoid carcinoma, inverted ductal papilloma, sialadenoma papilliferum, intraductal papilloma, and cystadenoma.
For superficial and small mucoceles, no treatment is recommended because they can heal spontaneously within 2 to 3 weeks.4 For those lesions that persist or are larger, the treatment of choice is surgical excision of the mucocele as well as the immediate surrounding minor salivary glands.5 The mucocele may recur if involved glands are not completely resected. Alternative treatment options include corticosteroid injection and cryotherapy.