Bluish floor of mouth swelling with a cervical component

§Chief complaint

Swelling under the tongue and in the neck for 4 months

§Medical & dental history

• 01Nil relevant
• 02Nil relevant

§Clinical examination

• 01Soft, bluish, translucent swelling of the left floor of mouth elevating the tongue
• 02Painless soft swelling in the left submandibular region, non-tender, no skin change
• 03Wharton duct orifice patent with normal saliva
• 04No trismus or airway compromise

§ figuresFigures (3)

Verified open-access images only, reproduced for education under their stated licences · no AI-generated or illustrative artwork · Ranula figures pending faculty review.

§Differential diagnosis

§Final diagnosis

Plunging (cervical) ranula arising from the left sublingual gland

A ranula that extends below the mylohyoid presents as a combined oral and cervical swelling. Being a pseudocyst of extravasated mucus from the sublingual gland, definitive treatment requires removal of that gland, not just the cyst.

§Investigations

• 01Ultrasound neck — anechoic collection extending through the mylohyoid
• 02MRI — high T2 signal 'tail sign' passing posterior to mylohyoid
• 03Aspiration — viscous, mucin-rich fluid with high amylase

§Treatment plan

• 01Excision of the ipsilateral sublingual gland with evacuation of the pseudocyst
• 02Intraoral approach preferred; cervical approach rarely needed
• 03Counsel on lingual nerve and Wharton duct risk

§Surgical procedure

• 01Intraoral floor of mouth incision lateral to the duct
• 02Wharton duct and lingual nerve identified and preserved
• 03Sublingual gland excised, pseudocyst decompressed
• 04No drain; primary closure

§Histopathology report

Mucin pool bounded by granulation tissue without epithelial lining, with adjacent sublingual gland tissue. Consistent with ranula (mucous extravasation pseudocyst).

§Follow-up & outcome

• 01Cervical swelling resolved within 3 weeks
• 02Transient lingual paraesthesia resolved by 6 weeks
• 03No recurrence at 18 months

§Clinical pearls / learning points

• 01Marsupialisation alone has high recurrence; sublingual gland excision is the definitive treatment.
• 02A neck lump with no oral component can still be a plunging ranula — check the amylase in the aspirate.
• 03The lingual nerve crosses under Wharton duct — identify both before dissecting.

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