A ranula (Latin word rana, meaning frog) describes a blue, translucent swelling in the floor of the mouth,
reminiscent of the underbelly of a frog. It is an uncommon type of mucus-filled cyst (mucocœle) arising
from the sublingual or submandibular salivary glands in the floor of the mouth.
|Ranulas / Ranulæ & Their Treatment
Photos of ranulæ present in the floor of the mouth, either occupying
both sides (opposite) or just one side (below).
The structure is essentially the same as other mucocœles, though there is usually an epithelial lining (i.e. lined by
Ranulæ are usually either one-side or the other in the floor of the mouth and 2 - 3 cm in diameter. Occasionally,
they extend across the whole of the floor of the mouth.
A ranula is most commonly observed as a bluish cyst located below the tongue. It may fill the mouth and raise the
tongue. Typically, these are painless masses that do not change in size in response to chewing, eating or
swallowing but may interfere with these functions (speech or chewing / eating). Occasionally, pain may be involved.
Ranulæ are rare. In one study of 1303 salivary gland cysts, only 42 were ranulæ. The reported male-to-female
ratio of occurrence is 1:1.3. Ranulæ tends to occur most frequently in the second and third decades of life, with an
age range of 3 - 61 years.
Ranulæ are formed from 1 of 2 processes:
1. Partial obstruction of a sublingual duct can lead to formation of an epithelial-lined retention cyst. This is
unusual, occurring in less than 10% of all ranulæ.
2. Trauma can lead to formation of ranulæ. With trauma, if a duct is obstructed, secretory back-pressure
builds leading to salivary duct rupture with mucus being forced into the surrounding tissues. Alternately, trauma
causes direct damage to the duct or acini, leading to mucus extravasation - a pseudocyst then forms. The more
appropriate term for this may be Mucus Escape Reaction (MER).
MRI is the most sensitive imaging study to evaluate the sublingual gland and its pathologic states.
Sublingual glands and their pathologic states are difficult to visualise with ultra-sound.
Obtaining a specimen for pathology is essential, not only for histologic confirmation but also because the presence
of squamous cell carcinoma arising in the cyst wall of a ranula and papillary cystadenocarcinoma of the
sublingual gland presenting as a ranula have been reported.
A recent though small study evaluated the effectiveness of orally administered Nickel Gluconate-Mercurius Heel-
Potentised Swine Organ Preparations D10/D30/D200, a homo-toxicological agent.
This medication acts to stimulate pseudocyst re-absorption and glandular repair and aids in improving the
physiologic functioning of the gland. In this study, Nickel
Gluconate-Mercurius Heel-Potentised Swine Organ Preparations D10/D30/D200 was administered regularly from
6 weeks to 6 months. Eight out of 9 ranulæ
responded to medical therapy.
Marsupialisation: Simple marsupialisation is the oldest and most widely reported treatment for ranulæ. It involves
'unroofing' the cyst and tacking the edges of the cyst to adjacent tissue.
Failure rates range from 61 - 89% with cysts recurring anywhere from 6 weeks to 12 months later.
Inferior compression on the cyst from the tongue leads to premature closure of the opened cyst leading to the high
recurrence rates. When conventional marsupialisation is undertaken, the wound margins tend to be in contact with
each other because of the narrow space and the movement of the tongue and the floor of the mouth. As a result,
the ranula tends to re-form and recur.
Packing the cyst cavity with gauze for 7 - 10 days improves the success rate.
Placement of suture / stitch or Seton: A silk suture or Seton can be placed through the surface of the cyst under
local anæsthesia. This is left in place while an epithelial tract forms, to allow for mucus drainage between the
surface and the underlying salivary glandular tissue.
Morbidity is minimal to non-existent and success has been good in limited studies.
Sclerosing Agents: Bleomycin and OK-432 have been used with success in treatment of ranulæ.
In one study, 31/32 patients (97%) achieved a disappearance or marked reduction in ranula size with injection of
OK-432. Nearly half of all patients experienced local pain or fever which resolved over several days. Intra-cystic
injection therapy with OK-432 is relatively safe and can be used as a substitute for surgery in the treatment of
ranulæ. Intra-cystic sclerosing injection with OK-432 has been proposed as a ranula primary treatment.
CO2 Laser: The CO2 laser has been used with a limited number of patients with good success to remove the cyst
and scar the gland enough to decrease risk for recurrence.
Post-operative follow-up at 6 months showed no recurrence, no lingual nerve dysæsthesia, no ductal disruption and
only minimal scar formation.
Radiation Therapy: In the rare patient who cannot tolerate surgery, radiation therapy is a viable alternative. Low
doses are effective. Xerostomia (dry mouth) can be avoided with low-dose therapy and shielding of the opposite
side parotid gland. The risk of radiation-induced malignancy is real but small.
Sublingual Gland Excision: The 'gold-standard' treatment for ranulæ is the excision of the ranula & the sublingual
gland. This removes the source of the mucus and thus significantly decreases the risk for recurrence.
A ranula larger than 1 cm should be treated by removal of the offending sublingual gland; other authors have
proposed that this treatment be used regardless of the size of the lesion.
Marsupialisation, excision of the ranula alone and excision of the sublingual gland combined with the ranula
resulted in recurrence rates of 66.67%, 57.69% and 1.20% respectively.
|Last Updated 17th October 2013