[Mucocele of the floor of the mouth (ranula): the result of interstitial salivary leakage].

Evidence in support of the theory that ranulas, with or without cervical extension, are caused by mucus escape from the sublingual gland is discussed. Our experience with 24 patients with large oral and cervical mucoceles is presented. In 2 of these patients a communication between Wharton's duct and the mucocele was demonstrated, presenting visible evidence for the mucus escape theory. Resection of the sublingual gland will cure the majority of large mucoceles of the floor of the mouth. However, the submandibular duct must also be examined in case this gland is also involved. Points in the operative technique are discussed. Although complete removal of the mucocele lining appears to be unnecessary, thorough removal of the mucus content is essential.