Ranula is a blue translucent swelling in the floor of the mouth ... it's like the underbelly of a frog . Ranulas may be classified based on their site of presentation : 1 into oral : they're just in the floor of mouth . 2 plunging : they are less commonly than the oral form . 3 mixed lesions . Diagnosis : 1 CT Scanning 2 Ultrasonography 3 MRI Surgical Treatment : 1 Marsupialization 2 removal of sublingual gland