Mucocoele

  • A mucococele (also mucocele) is the accumulation of mucus in either the connective tissue of within a salivary duct
  • The term encompasses both mucus extravasation phenomenon and mucous retention cyst

EpidemiologyEdit

  • No gender predilection[1]
  • Average age onset is 25 years[1]

Clinical FeaturesEdit

 
Mucocoele lower lip
  • Usually presents as recurrent swelling with intermittent mucous discharge (patients commonly report "drainage and re-filling")
  • Commonly there is a history of trauma to the site but this is not always the case
  • May develop at any site, but common locations are:[1]
    • Lower labial mucosa (81.9%)
    • Floor of mouth (5.8%) ← known as a ranula
    • Ventral tongue (5.0%)
    • Buccal mucosa (4.8%)
  • Rare in upper lip
  • Clinically appears translucent or bluish in colour (∵ of mucous contents)
    • Transillumination is present if the lesion is large enough
  • Palpation is usually soft and can feel fluctuant

Differential DiagnosisEdit

  • Be suspicious of an alternative diagnosis at less common sites (e.g. in upper lip, tumours of minor salivary glands are more common)

Aetiology and PathogenesisEdit

 
Formation of mucocoeles
  • Not true cysts because there is no epithelial lining (technically, they are polyps)
  • Mucous extravasation phenomenon
    • Extravasation mucoceles are caused by a leaking of fluid from surrounding tissue ducts or acini
    • Usually secondary to trauma causing a rupture of the ducts
  • Mucus retention cyst
    • Retention mucoceles are formed by dilation of the duct secondary to its obstruction (sialolith or dense mucosa)

InvestigationsEdit

  • Diagnosis is made on histology and clinical examination

HistologyEdit

 
Histopathologic image of extravasation type mucocele of the lower lip. H & E stain.
  • Mucin surrounded by granulation tissue
  • As inflammation is usually also present neutrophils and foamy histiocytes are also identified

ManagementEdit

  • Surgical excision of the cyst and associated minor salivary gland (usually under local anaesthetic)
    • Key to avoiding recurrence is to eliminate the adjacent surrounding glandular acini and removing the lesion down to the muscle layer
  • Aspiration does not lead to a lasting benefit as the salivary glands quickly refill the mucocoele
  • Some reports of using cryotherapy and laser therapy

Prognosis and ComplicationsEdit

  • Lesions can recur (different rates reported by ~3%)[2]

Follow-upEdit

  • No routine follow-up needed
  • Usually suitable for results to be presented to patient using remote consultation (telephone or results in post)

ReferencesEdit