Mucocele and ranula: bluish swellings from salivary glands
- Oral pathology
A soft bluish bubble on the inner lower lip is usually a mucocele from a damaged minor salivary gland. Under the tongue, a larger one is a ranula.
See it in 3D: Sublingual gland · Submandibular gland · Mylohyoid
What it is
A mucocele forms when the duct of a minor salivary gland is torn, usually by biting, and mucus leaks into the tissue. It appears as a soft, painless, bluish or translucent dome, most often on the inner lower lip, that may burst and refill. A ranula is the same process from the sublingual gland, forming a larger bluish swelling in the floor of the mouth to one side. A «plunging» ranula passes through or around the mylohyoid muscle and presents as a soft swelling in the neck. Other common lumps include the fibroma (a firm pink nodule from irritation) and the pyogenic granuloma (a red, bleeding lump, frequent in pregnancy).
How to recognise it
- Mucocele: lower lip, bluish dome, history of lip biting.
- Ranula: floor of the mouth, one side, from the sublingual gland.
- Plunging ranula: soft neck swelling under the jaw.
- Upper lip lumps are less often mucoceles and more often salivary tumours.
- Pyogenic granuloma bleeds easily and is common on the gums in pregnancy.
Differential and risks
- A firm, non-fluctuant lump of the upper lip or palate should be biopsied to exclude a salivary gland tumour.
- A floor-of-mouth swelling with fever and pain is infection (or Ludwig angina), not a ranula.
- Repeated draining of a mucocele does not cure it; the damaged gland must be removed.
Next step / Initial management
- Small mucocele: may resolve; if it persists or recurs, refer to the dentist or oral surgeon for excision with the gland.
- Ranula: refer to maxillofacial or ENT surgery; treatment usually includes removing the sublingual gland.
- Firm lumps, upper-lip lumps, palatal lumps or any lesion that grows: refer for biopsy.
Test yourself
Think of the answer, then tap the question to see it.
What is the typical site and cause of a mucocele?
The inner lower lip, from a torn minor salivary gland duct after biting.
Which gland gives rise to a ranula?
The sublingual gland.
How does a plunging ranula present?
As a soft swelling in the upper neck, after passing through or around the mylohyoid muscle.
Elsewhere in DurgiPedia
Connections
See it in 3D3
The structures of Durgical's 3D anatomy where it is found.
Educational content; it does not replace assessment by a dentist or doctor and is not a clinical instruction. For facial or neck swelling with difficulty swallowing or breathing, a knocked-out tooth or bleeding that will not stop, go to an emergency department at once.
Sources: Mucocele and Ranula (StatPearls Publishing (NCBI Bookshelf), 2023); Anatomy, Head and Neck, Salivary Glands (StatPearls Publishing (NCBI Bookshelf), 2023).
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Representative model, for educational purposes only.