Dermatologic Manifestations of Mucocele (Mucous Cyst)

Updated: Mar 27, 2019
  • Author: Christopher R Shea, MD; Chief Editor: William D James, MD  more...
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A mucocele (mucous cyst) is a benign, common, mucus-containing cystic lesion of the minor salivary glands in the oral cavity. The term mucocele is preferable to mucous cyst since most of these lesions are not true cysts, in the absence of an epithelial lining. The lesions can be located directly under the mucosa (superficial mucocele), in the upper submucosa (classic mucocele), or in the lower corium (deep mucocele). Two types of mucocele are distinguished, based on the histologic features: an extravasation cyst, formed by pools of mucus surrounded by granulation tissue (mucous pseudocyst, 92%), and a retention cyst with an epithelial lining (true mucous cyst, 8%). [1]



The mechanism of mucocele formation is unclear; however, a traumatic etiology rather than an obstructive phenomenon is considered more likely. Chaudhry et al showed that the escape of mucus into the surrounding tissue after severing the excretory salivary ducts led to mucocele formation. [2] The frequent location of the mucocele on the lateral aspect of the lower lip also supports the role of trauma as an etiologic factor. Although obstruction may play a role in the etiology of the mucocele, Chaudhry et al demonstrated that ligation and cutting of the salivary glands' ducts in rodents did not result in mucocele formation. [2] Lymphatic vessels may also contribute to the early stages of mucocele development. Specifically, the growing mucocele may induce a pressure gradient that causes lymphatics to swell with interstitial fluid, eventually rupturing and delivering this fluid back to the mucocele. [3]

In a study of 138 pediatric cases, Martins-Filho et al concluded that trauma is the main etiologic factor involved in the development of mucoceles in children. The mucus extravasation phenomenon is the most common histologic type in this age group. Although rare, the retention type seems to be more common in lesions on the floor of the mouth. [4]

After reviewing 1824 adults, Chi et al confirmed previous findings concerning the clinicopathologic features of oral mucoceles. Although special variants occur only infrequently, they need to be identified to avoid misdiagnosis. [5]



A traumatic etiology is favored for mucoceles. Animal models and the location of these lesions in areas of high traumatic exposure support this theory. [6, 7, 8, 9]




The prevalence of oral mucocele is 2.5 lesions per 1000 population. [10]


Mucoceles are most frequent in whites.


The incidence of mucocele is about equal in males and females. [11]


Although patients of all ages can be affected, more than half of mucocele cases occur in those younger than 30 years. In a large oral pathology series in children and adolescents, mucocele was the most common entity diagnosed (33% of cases), and the lip mucosa was the site most often involved (48%). [12] However, mucocele is uncommon in neonates and infants. [13] Very rarely, congenital onset has been reported. [14]

Mucous retention cysts are more frequent in older persons; conversely, the majority of mucoceles in younger patients represent the extravasation type. [15]

Mucoceles of the glands of Blandin-Nuhn (present on the ventral surface of the tongue) appear to be more prominent in young patients. [15]



Mucocele, a benign condition, is self-limited in most cases. Patients with mucoceles have an excellent prognosis; however, recurrence is common unless the associated salivary gland is resected.