My doctor says I have a ranula in my mouth. What is it? What can be done?

A Ranula (frog’s belly) is a purple, soft, painless swelling on one side of the floor of your mouth under the tongue. It occurs due to obstruction or damage to the drainage tubes of one of the small glands called the sublingual gland. Mucoid saliva then collects under the mucosa resulting in a sack. This cyst can be a simple one confined to the floor of the mouth or it may extend through the floor of mouth muscles and present in the neck (a plunging ranula)

What is ranula?