A bluish swelling under the tongue that appears and disappears is MOST likely:

Correct answer: D. Ranula

• A. Incorrect. Lymphangiomas are pale/yellowish, multilocular lesions — not typically blue and fluctuating.
• B. Incorrect. A dermoid cyst in the floor of mouth is a midline developmental cyst — typically NOT blue and NOT fluctuating.
• C. Incorrect. Mucoceles are most commonly found on the LOWER LIP (from minor salivary gland injury) and are usually small (few mm). Under-tongue bluish lesions that fluctuate in size are classic ranula.
• D. Correct. A RANULA is a mucus retention cyst (pseudocyst) of the SUBLINGUAL GLAND or minor salivary gland in the FLOOR OF THE MOUTH. It appears as a BLUE, translucent, dome-shaped swelling under the tongue that can fluctuate in size (coming and going) as mucus accumulates and disperses. The blue color = Tyndall effect from thin overlying mucosa.