Introduction
Background
A mucous cyst (MC) is a benign, common, mucus-containing cystic lesion of the minor salivary glands in the oral cavity. Some authors prefer the term mucocele 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 MCs occur based on the histologic features of the cyst wall: a mucous extravasation cyst formed by mucous pools surrounded by granulation tissue (92%) and a mucous retention cyst with an epithelial lining (8%).
Pathophysiology
The mechanism of formation of the MC is not totally clear; however, a traumatic etiology rather than an obstructive phenomenon is favored. Chaudhry et al showed that the escape of mucus into the surrounding tissue after severing the excretory salivary ducts led to the formation of the MC. The frequent location of the MC in 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 MC, Chaudhry et al demonstrated that the ligation and cutting of the salivary glands' ducts in mice and rats did not create the MC.
Frequency
United States
The prevalence of an oral MC is 2.5 lesions per 1000 population.
Mortality/Morbidity
This benign condition is self-limited in most cases.
Race
A MC is most frequent in whites.
Sex
The sexual incidence is about equal.
Age
Although patients of all ages can be affected, more than one half of MC cases occur in those younger than 30 years. Mucous retention cysts are more frequent in older persons than in younger persons.
Clinical
History
The clinical presentation varies by the type and the location of the lesion.
- People with superficial MCs may complain of single or multiple blisters that often spontaneously burst, leaving shallow ulcers.
- These lesions completely heal in a period of a few days.
- Sometimes, lesions recur in the same site.
- The classic MC presents as a shiny, dome-shaped papule that waxes and wanes over several months.
- An MC located in the deep soft tissue has a slow growth phase, resulting in a firm, deep mass.
- Rare cases have been described in the neck arising from ectopic salivary glands; these lesions are associated with cheilitis glandularis apostematosa.
Physical
The clinical presentation depends on the depth of the lesion.
- Superficial MC
- The mucus accumulates immediately below the mucosa, resulting in small translucent vesicles (0.1-0.4 cm in diameter) in the soft palate, the retromolar region, and the buccal mucosa.
- In time, these blisters burst spontaneously or by trauma, leaving shallow ulcers or erosions.
- Classic MC
- This form presents as a collection of mucous material in the upper submucosa producing a well-defined, mobile, and painless dome-shaped swelling.
- These lesions often exhibit a smooth, blue surface.
- The size varies from a few millimeters to several centimeters in diameter, but 75% of the lesions are smaller than 1 cm in diameter.
- Eventually, the surface of the lesion turns irregular and whitish due to multiple cycles of rupture and healing caused by trauma or puncture.
- The most frequent locations are in the lower lip, the floor of the mouth, the cheek, the palate, the retromolar fossa, and the dorsal surface of the tongue; however, these lesions spare the upper lip.
- Most of the larger lesions commonly affect the floor of the mouth; these are called ranula because of the similarity to the throat pouch of frogs. This collection of mucus can extend beyond the oral cavity and as far as the upper mediastinum or skull base.
- When the mucus accumulates in the deep soft tissues, the presentation is of an enlarging, painless mass assuming the pink coloration of the mucosa.
Causes
A traumatic etiology is favored. Animal models and the location of these lesions in areas of high traumatic exposure support this theory.
More on Mucous Cyst |
Overview: Mucous Cyst |
| Differential Diagnoses & Workup: Mucous Cyst |
| Treatment & Medication: Mucous Cyst |
| Follow-up: Mucous Cyst |
| Multimedia: Mucous Cyst |
| References |
| Next Page » |
References
Arendorf TM, van Wyk CW. The association between perioral injury and mucoceles. Int J Oral Surg. Oct 1981;10(5):328-32. [Medline].
Bhaskar SN, Bolden TE, Weinmann JP. Experimental obstructive adenitis in the mouse. J Dent Res. Dec 1956;35(6):852-62. [Medline].
Bhaskar SN, Bolden TE, Weinmann JP. Pathogenesis of mucoceles. J Dent Res. Dec 1956;35(6):863-74. [Medline].
Bouquot JE, Gundlach KK. Oral exophytic lesions in 23,616 white Americans over 35 years of age. Oral Surg Oral Med Oral Pathol. Sep 1986;62(3):284-91. [Medline].
Cataldo E, Mosadomi A. Mucoceles of the oral mucous membrane. Arch Otolaryngol. Apr 1970;91(4):360-5. [Medline].
Chaudhry AP, Reynolds DH, LaChapelle CF, Vickers RA. A clinical and experimental study of mucocele (retention cyst). J Dent Res. Nov-Dec 1960;39:1253-62. [Medline].
Cohen L. Mucoceles of the oral cavity. Oral Surg Oral Med Oral Pathol. Mar 1965;19:365-72. [Medline].
Correll RW, Friedlander AH. Painless swelling of the lower lip. J Am Dent Assoc. Nov 1988;117(6):761-2. [Medline].
Crean SJ, Connor C. Congenital mucoceles: report of two cases. Int J Paediatr Dent. Dec 1996;6(4):271-5. [Medline].
Davis SB, Simon JH. Mucocele: a potential complication to endodontic surgery. J Endod. Oct 1994;20(10):515-7. [Medline].
Dent CD, Svirsky JA, Kenny KF. Large mucous retention phenomenon (mucocele) of the upper lip. Case report and review of the literature. Va Dent J. Jan-Mar 1997;74(1):8-9. [Medline].
Eveson JW. Superficial mucoceles: pitfall in clinical and microscopic diagnosis. Oral Surg Oral Med Oral Pathol. Sep 1988;66(3):318-22. [Medline].
Frame JW. Removal of oral soft tissue pathology with the CO2 laser. J Oral Maxillofac Surg. Nov 1985;43(11):850-5. [Medline].
Galloway RH, Gross PD, Thompson SH, Patterson AL. Pathogenesis and treatment of ranula: report of three cases. J Oral Maxillofac Surg. Mar 1989;47(3):299-302. [Medline].
Harrison JD. Salivary mucoceles. Oral Surg Oral Med Oral Pathol. Feb 1975;39(2):268-78. [Medline].
Harrison JD, Garrett JR. Mucocele formation in cats by glandular duct ligation. Arch Oral Biol. Oct 1972;17(10):1403-14. [Medline].
Ishida CE, Ramos-e-Silva M. Cryosurgery in oral lesions. Int J Dermatol. Apr 1998;37(4):283-5. [Medline].
Jensen JL. Superficial mucoceles of the oral mucosa. Am J Dermatopathol. Feb 1990;12(1):88-92. [Medline].
Kopp WK, St-Hilaire H. Mucosal preservation in the treatment of mucocele with CO2 laser. J Oral Maxillofac Surg. Dec 2004;62(12):1559-61. [Medline].
Lattanand A, Johnson WC, Graham JH. Mucous cyst (mucocele). A clinicopathologic and histochemical study. Arch Dermatol. Jun 1970;101(6):673-8. [Medline].
Mandel L. Ranula, or, what''s in a name?. N Y State Dent J. Jan 1996;62(1):37-9. [Medline].
Morton RP, Bartley JR. Simple sublingual ranulas: pathogenesis and management. J Otolaryngol. Aug 1995;24(4):253-4. [Medline].
Neumann RA, Knobler RM. Treatment of oral mucous cysts with an argon laser. Arch Dermatol. Jun 1990;126(6):829-30. [Medline].
Oliveira DT, Consolaro A, Freitas FJ. Histopathological spectrum of 112 cases of mucocele. Braz Dent J. 1993;4(1):29-36. [Medline].
Robinson L, Hjorting-Hansen E. Pathologic changes associated with mucus retention cysts of minor salivary glands. Oral Surg Oral Med Oral Pathol. Aug 1964;18:191-205. [Medline].
Sela J, Ulmansky M. Mucous retention cyst of salivary glands. J Oral Surg. Aug 1969;27(8):619-23. [Medline].
Standish SM, Shafer WG. The mucus retention phenomenon. J Oral Surg Anesth Hosp Dent Serv. Jul 1959;17(4):15-22. [Medline].
Standish SM, Shafer WG. Serial histologic effects of rat submaxillary and sublingual salivary gland duct and blood vessel ligation. J Dent Res. Dec 1957;36(6):866-79. [Medline].
Toida M, Ishimaru JI, Hobo N. A simple cryosurgical method for treatment of oral mucous cysts. Int J Oral Maxillofac Surg. Dec 1993;22(6):353-5. [Medline].
Weir TW, Johnson WC. Cheilitis glandularis. Arch Dermatol. Apr 1971;103(4):433-7. [Medline].
Wilcox JW, History JE. Nonsurgical resolution of mucoceles. J Oral Surg. Jun 1978;36(6):478. [Medline].
Yamasoba T, Tayama N, Syoji M, Fukuta M. Clinicostatistical study of lower lip mucoceles. Head Neck. Jul-Aug 1990;12(4):316-20. [Medline].
Yoshikawa F, Okunishi Y, Sakuda M. Mucous cyst forming on the dorsal surface of the tongue: report of a case. J Oral Maxillofac Surg. Jul 1994;52(7):770-1; discussion 772. [Medline].
Zhang M, Hayashi H, Fukuyama H, et al. Traumatic neuroma in the lower lip arising following laser/cryosurgery to treat a mucocele. Oral Dis. May 2003;9(3):160-1. [Medline].
Further Reading
Keywords
MC, mucocele, mucus extravasation phenomenon, mucus escape reaction, mucus retention cysts, mucous extravasation phenomenon, mucous escape reaction, mucous retention cysts
Overview: Mucous Cyst