Mucocele is a painless mucus filled lump commonly found in the inner part of the lips. This benign looking mass usually contains clear fluid. Mucocele results from the blockade and injury of any of the minor salivary glands.
Mucocele presents as a small fluid filled sac most commonly seen in the inner lip area. It appears bluish in clear and is often painless to palpation. Other less common sites of mucocele include the tongue, palate, cheek surface, and the floor of mouth.
Although these lesions are benign, they are generally annoying to the patients because they interfere speech and eating.
Mucocele and ranula are easily diagnosed clinically.
Sometimes imaging studies of larger lesions and those with any obstructing sialolith may be required. Computed Tomography (CT-scan) and Magnetic Resonance Imaging (MRI) are used to investigate large plunging and cervical ranulas .
Ultrasonography has also been used in the elucidation of the symptomatic and bothersome oral mucocele and ranula .
In most cases, superficial oral mucocele requires biopsy and histopathologic study . Mucus from the pseudocysts may also be aspirated using a fine needle syringe for evaluation. In case of retention mucinous cysts, excision biopsy may be required to deroof the cyst and restore the patency of the ducts.
Multiple mucoceles on the lip area are treated with topical clobetasol 0.05% with gamma linolenic acid to control flare ups and recurrences . Mucoceles and ranulas in infants and children are usually observed for a few months before active interventions are initiated. In children, up to 44% of these oral lesions resolve spontaneously within 3 months. Persistent symptoms require excision surgery or fluid aspiration with a fine needle. Micromarsupialization techniques may be attempted on pediatric patients to prevent the recurrence of these pseudocysts. Other cases can be successfully treated using cryotherapy, laser surgery or electrocauterization.
Mucocele usually results from the blockage of the mucus ducts of the lips and the base of the mouth. The mucus ducts are obstructed due to trauma to the mouth area. The irritation in the obstructed mucus duct causes the patient to passively suck on the lips causing a mucus filled growth on the lips. Any form of tattooing and lip piercing can also predispose to the formation of mucocele.
In general, mucocele occurs in 1 out of 500 individuals. In the United States, mucocele represents the 17th most common oral lesion in the clinics with a country wide prevalence rate of 14 cases per 10,000 population. In children, the prevalence rate is 4 cases out of 10,000 children aging 2 to 17 years . Rarely, a congenital mucocele can occur in the newborn .
Superficial mucocele represents 6% of the cases of oral mucocele. This type of pseudocyst abounds in the soft palate region and the retromolar regions of the palate. True ranulas in the oral cavity only represents 1% to 10% of the total cases of mucocele. In Sweden, mucocele has a prevalence rating of 11 cases per 10,000 population . Morbidity in mucocele are only associated with plunging ranulas that can cause airway obstruction when they grow large enough . There are no racial and sexual predilection for mucocele formation. Almost 70% of mucocele cases occur at age 20 or younger while mucus retention cysts peak during the fifth to sixth decade of life.
The pathophysiology of mucocele and ranula stems from the obstruction and disruption of the mucus secretion of the salivary glands. Any traumatic insults to the ductul nomenclature will advertently cause the extravasation of the mucus in the neighboring tissues causing a soft blister in the affected area. Hypertension due to ductal obstruction can cause rupture of the acinar structure causing an aberrant flow of mucus in the nearby structures. Traumatic injuries to the acinar and lobular structures of the salivary glands can contribute to the pathogenesis of the disease process .
In some cases of non-traumatic superficial mucoceles, an immunologic causation is sometimes implicated. The aggressive nature of the pseudocyst is attributed to the progressive secretion of proteolytic enzymes that assist its expansive nature . Some mucocele are caused by ductal obstruction from sialoliths or inspissated secretions formed by the salivary glands themselves.
There are no known modifiable activities to prevent the occurrence of mucoceles. Children and adults are advised to avoid the intentional sucking of the lips in between the teeth to prevent its development.
Mucocele or oral ranula is a pseudocyst that form in the mouth due to the extravasation of mucus due to obstruction or trauma to the salivary gland. Mucocele is sometimes referred to as a mucus retention cyst which originates from a minor salivary gland.
Ranula is a mucocele that originates from a major salivary gland and is seen in the floor of the mouth. It is classified as cervical and plunging depending on its location and origin.
Obstruction of the duct of a minor salivary gland with gradual acumulation of secretions causes the gland to swell. It is then known as a mucocele and it usually appears on the inner surface of the lip as a painless, blue swelling. Trauma and small stones also cause obstruction in the duct of the salivary gland leading to mucocele formation. Small mucoceles often resolve spontaneously within 3 months without any active treatment. In other cases, surgery and operative techniques may be needed to remove the mucocele.