Ranula

RANULA, a tumor resembling the submental (throat) pouch of a frog; it is usually located between the tongue and the lower jaw on one or the other side of the midline (see figure); it belongs to the type of retention cysts of the salivary glands, which are frequently observed in the oral cavity and run their course unnoticed by the patient unless they are subjected to trauma and infection. When significantly developed, the tumor displaces the tongue upward and backward. Its anterior wall is thinned, of a pale blue color, due to the translucent transparent fluid; frequently, a salivary duct passes through the wall of the tumor, remaining patent. The tumor is filled with a thick, transparent, saliva-like content (Ptyalin, Rhodan, Kalium) drawn out into threads. The cyst may be congenital or develop slowly in subsequent years of life. In childhood, it interferes with suckling and swallowing, sometimes hinders breathing; in adults, it prevents proper pronunciation and spoils facial expression. Developing in childhood, it affects the growth and development of the lower jaw; in adults, when large, it can bulge the floor of the oral cavity from below. Regarding the origin of the tumor, various opinions exist. The most acceptable explanation is that the cyst forms along the course of an inflamed and altered small duct of the submandibular gland, wherein the enlargement of the cavity occurs not from the retention of saliva, but as a result of the transudation of fluid from the capillaries and mucous membrane of the degenerated epithelium. The origin of the ranula from the glands of the tip of the tongue or as a result of blockage of the main duct of the sublingual gland is unlikely. Ranula is more common in women. The diagnosis is made on the basis of the described signs of the cyst. In addition, the characteristic position of this cyst is to the side of the midline, which distinguishes it from the dermoid cyst of the floor of the oral cavity protruding in this region, which is usually located along the midline. Ranula often runs its course unnoticed by the patient—what forces them to consult a doctor is difficulty in speaking or infection of the contents through the thin wall. The explanation of the origin of the ranula from the inclusion of endodermal elements during the closure of embryonic clefts deserves attention, which is very probable given the complexity of the developmental history of the floor of the mouth, although studies in this direction have not yet yielded a definitive result. According to another view, the cyst forms from a branch of the ductus thyreoglossi (Bochdalek's pouches) and can occupy a typical position on the floor of the mouth, as Neumann tries to prove. Treatment by puncture does not lead to the goal, and injections of irritating substances are also ineffective. Radical enucleation of the cyst is difficult and unsafe regarding the possibility of damaging the excretory duct of the sublingual salivary gland. The best method should be considered the excision of the anterior wall to a greater or lesser extent and the suturing of the cyst mucosa to the oral mucosa.