A soft, bluish, fluctuant, dome-shaped swelling on the lower lip of a young patient that changes in size, often after lip biting, is most likely a:

A mucocele is a mucus extravasation phenomenon from a severed or traumatized minor salivary gland duct (commonly on the lower lip), presenting as a soft bluish dome that varies in size and may rupture and recur. Treatment is excision including the feeding minor gland.Other options: SCC is indurated and non-healing; a hemangioma blanches and is vascular/congenital; a ranula is the analogous lesion on the floor of the mouth (sublingual gland).Key exam takeaway: A bluish fluctuant lower-lip swelling after trauma is a mucocele; excise the lesion and associated minor gland to prevent recurrence.