clincal review of ranulas

Clinical review of 580 ranulas

Yi-Fang Zhao, DDS, MSc,a YuLin Jia, DDS, MSc,b Xin-Ming Chen, MD,c and

Wen-Fen Zhang, DDS, MSc,a Wuhan, People’s Republic of ChinaWUHAN UNIVERSITY

Objective. The purpose of this paper was to compare clinical features among 3 patterns of ranula and the recurrence ratesof each when treated by different surgical methods.Methods. A retrospective review of clinical and pathologic records in 580 ranulas was undertaken. Ranulas wereclassified into 3 clinical types according to sites of the primary swelling: oral ranula, plunging ranula, and mixed ranula.Information was collected on age at presentation, sex, history of onset, sites of swelling, surgical methods, histologicalfindings, and outcome of treatment.Results. Ranula was most prevalent in the second decade of life and slightly more common in females (male to femaleratio of 1:1.2), but a distinct male predilection was noted for the plunging ranula (male to female ratio of 1:0.74). Oralranula was most commonly involved in the left side (left to right ratio of 1:0.62), while the plunging and mixed ranulawere commonly involved in the right side (left to right ratio of 1:1.38, 1:1.16 respectively). In the plunging ranula group,there were more patients who had the history more than 6 months. The recurrence rates of ranulas were not related toswelling patterns and surgical approaches, but intimately related to the methods of surgical procedures. The recurrentrates for marsupialization, excision of ranula, and excision of the sublingual gland or gland combined with lesion were66.67%, 57.69%, and 1.20%, respectively.Conclusion. Three patterns of ranula have similar clinical and histopathologic findings, although plunging ranula hassome different clinical features. Removal of the sublingual gland via an intraoral approach is necessary in themanagement of various clinical patterns of the ranula. Recurrence rates of ranulas of any type are excessive unless theinvolved sublingual gland is removed.(Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004;98:281-87)

Ranulas develop from extravasation of mucous after

trauma to the sublingual gland or obstruction of the

ducts.1,2 It typically has a bluish appearance that is

compared to a frog’s belly, hence the term ranula. When

it is a cervical swelling or mass without a prominent oral

swelling, the ranula may be misdiagnosed as thyro-

glossal duct cyst, dermoid or epidermoid cysts, vascular

malformations, and even submandibular sialoadenitis.

Clinicians have used several different methods of treat-

ment for ranulas. These include excision of the ranula via

either an intraoral or cervical approach, marsupiali-

zation, intraoral excision of the sublingual gland and

drainage of the lesion, and excision of the lesion and

aProfessor, Department of Oral and Maxillofacial Surgery, College &

Hospital of Stomatology, Wuhan University Wuhan, People’s

Republic of China.bOral Surgeon, Department of Oral and Maxillofacial Surgery,

College & Hospital of Stomatology, Wuhan University Wuhan,

People’s Republic of China.cClinical professor, Department of Oral Pathology, College &

Hospital of Stomatology, Wuhan University Wuhan, People’s

Republic of China.

Received for publication Oct 17, 2003; returned for revision Dec 2,

2003; accepted for publication Jan 28, 2004.

1079-2104/$ - see front matter

� 2004 Elsevier Inc. All rights reserved.

doi:10.1016/j.tripleo.2004.01.013

sublingual gland. Despite these treatments, many

patients have experienced recurrence and sometimes

larger lesions have occurred, eg, conversion of an oral

ranula into a plunging (cervical) ranula.3,4 This study

reports clinicopathological features of 3 clinical cat-

egories of ranula and the results of several surgical

methods for management of ranulas.

MATERIALS AND METHODSThis study was based on the relevant clinical details

and pathology reports from the patients’ records and

follow-up data. Our materials consisted of 606 cysts in

571 patients with ranula treated in the Department of

Oral and Maxillofacial Surgery at the Hospital of

Stomatology, Wuhan University, China, between the

years 1962 and 2002. All patients were treated surgi-

cally. Marsupialization was performed by excising the

superior wall of the lesion and suturing the inner wall to

the mucosa of the floor of the mouth. Some ranulas were

excised via an intraoral or extraoral approach. Excision

of oral ranula was accomplished by making a linear or

elliptical incision along the superior aspect of the ranula,

medial to the plica sublingularis. Excision of plunging

ranula was performed by a routine submandibular

incision. The ranula was freed by blunt dissection from

the adjacent structures including the sublingual gland.

When excision of the sublingual gland was chosen for

281

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282 Zhao et al September 2004

Fig 1. Age distribution of 571 patients with ranula.

management of ranula, the cyst was only evacuated

through the surgical field with no intention to dissect the

cyst wall. The majority of ranulas were surgically treated

by staff oral surgeons, whereas a few surgeries were

performed by junior surgeons under guidance of senior

oral surgeons. Tissues obtained at surgery were rou-

tinely sectioned and stained with hematoxylin-eosin for

microscopic examination. Sections were reviewed by 2

senior pathologists.

The age at presentation of ranula, course of the lesion,

location of the swelling, methods of surgical treatment,

and pathological findings were reviewed. Lesions were

classified into 3 clinical types according sites of the

primary swelling: oral ranula (intraoral swelling only),

plunging ranula (submandibular and/or submental

swelling without intraoral swelling), and mixed ranula

(intraoral and extraoral swelling). Clinical features were

compared among 3 patterns of ranula. All patients were

followed up postoperatively and they were contacted by

mail or telephone for failure to return. The follow-up

period of patients who had follow-up data ranged from 6

months to 26 years. Recurrence rates were analyzed and

compared in view of the site of involvement and methods

of treatment. Clinical observation, diagnosis, and follow-

up were made by staff oral surgeons. The chi-square test

was used to assess the significance of each variable

(SPSS Inc, Ver. 11.0, Chicago, Ill).

RESULTSThe ages of 571 patients at diagnosis are shown in

Fig 1. The youngest patient was 3 months old and the

oldest 80 years, with a peak frequency within the second

decade. There was a similar percentage among the

patients with 3 clinical patterns of ranulas. The gender

distribution was 260 males (45.53%) and 311 females

(56.47%), with a slight predilection of females. How-

ever, a distinct male predilection was noted for the

plunging ranula, with a 1 to 0.73 ratio (Table I), and the

difference was highly significant between oral and

plunging ranulas (P\.01). All patients were Chinese.

Five hundred and seventy-one patients had 580 cysts.

Three hundred and twenty-four cysts occurred in the left

and 256 in the right side. The plunging ranula was most

commonly involved in the right side (Table II). The

difference was highly significant between oral and

plunging ranulas (P\.01) and significant between oral

and mixed ranulas (P\.05). There were 9 bilateral

ranulas, in which 3 cases of ranula occurred simulta-

neously and 6 lesions occurred in the opposite side 4

months to 2 years and 7 months, respectively, after

a ranula in the involved side was treated.

Most of patients with oral ranula presented with

a gradually enlarging swelling of the floor of the mouth.

The swellings were round or oval and fluctuant (Fig 2).

When it was significantly large, ranula produced

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Volume 98, Number 3 Zhao et al 283

deviation of the tongue and also crossed the midline. The

swelling was painless and did not change in size on

gustatory stimulations except in 13 cases, where there

were intermittent episodes of swelling of the sub-

mandibular gland on the same side during eating. Most

lesions were present for only a few days to 3 weeks, but

some patients had them for months or even years before

seeking treatment. In the plunging ranula group, there

were more patients who had the history more than 6

months (Table III); the difference was highly signifi-

cant compared with oral and mixed ranulas (P\.01).

Nineteen patients had a complaint of pain and rapidly

increased swelling following aspiration of ranula. Twenty-

four oral swellings drained spontaneously at intervals

but at no time completely disappeared. Seventeen pa-

tients were able to relate the development of the cyst

to trauma.

The majority of them were 2 to 3 cm in diameter

but a few mixed or plunging ranulas extended from

the floor of the mouth into the submandibular space,

parapharyngeal space posteriorly, or even into the

carotid triangle inferiorly. Intraoral lesions were blue

and fluctuant whereas plunging lesions were the color of

normal mucosa or skin. The plunging ranula typically

manifests as a soft, painless, and nonmobile swelling in

the neck (Fig 3). The mixed ranula had both intraoral and

extraoral swellings (Fig 4), usually intraoral swelling

was found earlier than cervical lesion. Oral and mixed

ranulas gave few diagnostic problems but plunging

lesions could be confused with lymphatic malformations

in 7 cases, venous malformations in 2, and thyroglossal

tract cyst in 1. Preoperative aspiration showed viscous

colorless liquid or viscous amber-colored fluid in 63

cases and aspiration got over 50 mL viscous fluid in 2

cases.

Surgery was performed under local or general

anesthesia. Five hundred and seventy-one patients had

606 procedures, in which 580 were for primary lesions

Table I. Sex distribution of 571 patients with ranula

Patterns Case no. Male Female M:F ratio

Oral 387 161 226 1:1.40

Plunging 118 68 50 1:0.74

Mixed 66 31 35 1:1.13

Total 571 260 311 1:1.20

Table II. Site distribution of 580 ranulas

Patterns Case no. Left Right L:R ratio

Oral 394 243 151 1:0.62

Plunging 119 50 69 1:1.38

Mixed 67 31 36 1:1.16

Total 580 324 256 1:0.79

and 26 for recurrent cysts. Of 606 procedures, there were

28 excisions of the ranula, 9 marsupializations, 356

excisions of the sublingual gland, and 213 excisions of

the gland in combination with ranula. The majority of

procedures were performed through the mucosa of the

floor of the mouth (intraoral approach), but the access of

surgical explorations was through the submandibular

incision in 58 plunging or mixed ranulas. When the

lesion was operated via the submandibular approach, it

was often found that on elevation of the platysma

muscle, there was a thin-walled cyst intimately associ-

ated with the anterior portion of the submandibular

gland. However, further dissection showed that the lesion

was in connection with the sublingual gland (Fig 5). Of

58 lesions treated via the submandibular incision, the

cyst was resected in 3 cases, in continuity with the

sublingual gland in 36, and with the submandibular and

sublingual glands in 19 cases.

Four hundred and fifteen patients (450 cysts) obtained

more than 6 months of follow-up data and recurrence

was found in 21 cases after the first treatment. When we

considered each procedure as 1 operation, the recurrence

rates for marsupialization, excision of the ranula, and

excision of the sublingual gland or excision of the gland

combined with lesion were 66.67%, 57.69%, and 1.20%,

respectively (Table IV). Ranulas treated by simple

excision or marsupialization had a significantly higher

recurrence rate than those of ranulas treated by excision

Fig 2. Clinical photograph of oral ranula presented as an oval

swelling of the right floor of mouth.

Table III. Comparison of the history among 3 clinical

patterns of ranulas

Patterns Case no. # 6 months >6 months

Oral 394 334(84.77) 60(15.23)

Plunging 119 76(63.87) 43(36.13)

Mixed 67 47(70.15) 20(19.85)

Total 580 457(78.79) 123(21.21)

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of the sublingual gland or removal of both the gland and

ranula (P\.01). The recurrence rates of ranulas were not

related to swelling patterns (P > .05), but intimately

related to the methods of surgical procedures (Tables IV,

V). Twenty-one patients with recurrent ranula had

a second operation, namely excision of ranula in 8 and

excision of the lesion combined with the sublingual

gland in 13 cases. Of these cases, 5 had a second re-

currence, in which 4 developed from excision of ranula

and 1 from excision of both the lesion and the sublingual

gland. The third operation in all recurrences involved

simultaneous excision of the lesion and the sublingual

gland. This treatment resulted in a cure.

The pathological examination revealed that the cyst

wall consisted of fibroconnective or granulation tissue,

usually with a scanty or minimal degree of chronic in-

flammatory infiltration. The cyst-like space contained

mucus, histocytes, polymorphs, and lymphocytes. The

cystic cavity was occasionally lined with a small area of

ductal epithelium (Fig 6), which was observed in 11

lesions (1.82%). The adjacent salivary gland acini

showed some chronic inflammatory changes and part

of their ducts were dilated. In a few cases, the sur-

rounding loose edematous stroma showed numerous

dilated, blood-filled vascular channels (Fig 7). The

histologic findings were not significantly different

between the oral and plunging or mixed ranula. In 19

submandibular glands excised, 13 had chronic inflam-

matory features under microscope.

DISCUSSIONObstruction of excretory ducts or extravasation and

subsequent accumulation of saliva from the sublingual

gland in the tissue are responsible for the formation of

ranulas.1,2,5,6 Ranulas or mucoceles of the floor of the

mouth occur in approximately 5% of patients un-

dergoing submandibular duct relocation for the man-

Fig 3. Plunging ranula showing the swelling in the right

submandibular region without evidence of intraoral involve-

ment.

agement of uncontrollable sialorrhea.7 In our study, 17

patients (2.98%) demonstrated the history of trauma or

surgery in the floor of the mouth.

Clinically, the oral ranula, though they are generally

small to medium in size, displaces the tongue, and

interferes with oral function. Very large oral ranulas or

ranulas located in the area of the caruncula sublingualis

Fig 4. Mixed ranula originating from the right sublingual

gland in 13-year-old boy, showing obvious swelling of floor of

mouth crossing midline (A) with involvement of the submental

and right submandibular regions (B).

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may lead to partial obstruction of the Wharton duct

resulting in submandibular swelling during eating. In

this study, obstructive symptoms were observed pre-

operatively in 16 patients, in whom 13 postoperative

specimens showed chronic inflammation in the sub-

mandibular gland parenchyma. The formation of the

plunging ranula may originate from sublingual gland

mucus leakage in the deeper areas of the gland, and the

fluid drainage inferior into the submandibular space as

a result of gravity. Therefore, the lesion less interferes

with function, and patients with the plunging ranula may

seek treatment later than the patients with oral ranula. It

is unclear why the plunging ranula more commonly

affects males more than females and the sublingual gland

in the right side more than in the left side.

The diagnosis of ranula is based principally on the

clinical examination and sometimes on computerized

tomographic or magnetic resonance imaging findings for

the plunging lesion. When it is an isolated oral lesion, the

diagnosis is generally easily accomplished. The suspi-

cion of the mixed ranula is definitely increased if

Fig 5. Recurrent plunging ranula. A, Recurrence occurred

after excision of the lesion via the left submandibular approach

eight months ago. B, Multiple-cystic lesion under the

platysmal muscle. The cyst connected with the deep portion

of the sublingual gland by a duct-like structure. No recurrence

five years after excision of the ranula and the sublingual gland.

evidence of a ranula has been seen intraorally with

cervical swelling. In our study, it was demonstrated that

there was a spectrum of clinical changes in the mixed

ranula over time and this ranula, in part at least,

developed from the oral ranula that was a lesion with

a longer history or recurrent lesion. However, when

ranulas present as a cervical swelling without an oral

component, differential diagnosis may be more difficult.

Other lesions that should be considered include

thyroglossal duct cysts, branchial cleft cysts, parathyroid

cysts, cervical thymic cysts, dermoid cysts, cystic

hygroma, and benign teratoma.8 If there is doubt about

the diagnosis, aspiration of mucous from the lesion and

a laboratory determination of amylase content should

make the diagnosis of ranula obvious.3 The plunging

ranula should be distinguished from a mucocle resulting

from the submandibular gland because of different

surgical treatment for them. In the case of the sub-

mandibular gland mucocele it is essential to excise the

lesion with the submandibular gland, and this is best

accomplished through use of a cervical approach.9 In the

case of the plunging ranula, however, excision of the

sublingual gland and drainage of the cyst via an intraoral

approach is the approach of choice. It is impossible to

distinguish from them clinically. However, mucoceles

originating from the submandibular gland are extremely

rare. Anastassov et al 9 reviewed the English literature

and found only 5 such cases. Computerized tomography

and specifically the presence of a so-called ‘‘tail’’ sign

are pathognomonic for the plunging ranula.9-11 The sign

is absent in mucoceles originating in the submandibular

glands. The findings during surgery are very important

for determining the origin of the lesion. When the

Table IV. Surgical methods and recurrence rates

OperationsCystno.

Recurrenceno.

Recurrencerate

Excision of ranula 26 15 57.69

Marsupialization 9 6 66.67

Excision of sublingual

gland

286 3 1.05

Excision of sublingual

gland and ranula

129 2 1.55

Total 450 26 5.78

Table V. Swelling patterns of ranulas and recurrence

rates

Patterns Cyst no. Recurrence no. Recurrence rate

Oral 306 21 6.86

Plunging 89 5 5.62

Mixed 55 0 0

Total 450 26 5.78

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plunging or mixed ranula was operated via the extraoral

approach, we observed a ductlike extension between the

lesion and the sublingual gland at the posterior margin of

the mylohyoid muscle, suggesting the origin of the lesion

from the sublingual gland.

Surgery is the mainstay for management of ranula.

Simple marsupialization has fallen into disfavor primar-

ily because the failure rate has been anywhere from

61% to 89%.7 Baurmash12 believes that simple mar-

supialization of relatively large lesions ([1.5 cm), which

usually have their origin from the deeper portion of the

sublingual gland, is a procedure without a sound

foundation from an anatomic, mechanical, or histolog-

ical standpoint. A new ranula generally will develop

within 6 to 8 weeks. Marsupialization with packing the

cyst cavity may reduce recurrence of ranula.12 Crysdale

et al7 reported that the recurrence rate was 100% in cases

with incision and drainage, 61% in cases of simple

marsupialization, and 0% in case of excision of the

ranula with or without sublingual gland excision. Parekh

et al3 reviewed 139 procedures in 89 cases of plunging

ranula; a recurrence rate of 70.5% was observed after

incision and drainage, 52.6% after marsupialization,

84.8% after excision of the lesion in the neck, 3.8% after

cervical excision of the lesion combined with excision

of the sublingual gland, and 0% after intraoral excision

of the sublingual gland and drainage of the cyst. Our

findings also clearly confirm that marsupialization or

excision of the ranula has a high recurrence rate and are

not suitable treatments.

As ranulas are usually extravasation pseudocysts

developing after disruption of sublingual gland ele-

ments, many authors advocate that excision of the

ipsilateral sublingual gland is the management approach

of choice.3,7,13,14 In the present study, it is demonstrated

that incomplete excision of the sublingual gland may

Fig 6. The part of the cyst lining was formed by a single or

double layer of ductal epithelial cells (hematoxylin-eosin stain,

original magnification 3 33).

lead to recurrence in 5 cases. Four oral ranulas received

excision of ranula and the sublingual gland through

a transoral approach, and another plunging ranula

underwent excision of both through a submandibular

incision, but recurrence occurred 4 to 19 months after the

operation, respectively. The second operation found that

the sublingual gland incompletely removed was associ-

ated with the cyst, suggesting that the residual secretory

acini remain active after partial excision of the sublingual

gland.

Ichimura et al15 treated 7 patients with a plunging

ranula. All patients underwent surgery via a cervical

approach. Although total sublingual gland excision was

not performed in 2 patients, no recurrence was observed

in any patient. They suggest that a cervical approach may

still be the method of choice for the first operation or for

salvage surgery after recurrence subsequent to intraoral

procedure if there is no swelling of the oral floor. Mizuno

and Yamaguchi16 suggest since a plunging ranula is due

to extravasation from the sublingual gland herniating

through the mylohyoid muscle, excision of the sub-

lingual gland followed by transoral drainage of the

plunging ranula is regarded as the best treatment. Our

results show that the intraoral excision of the offending

sublingual gland is a simple and curable procedure with

minimal potential complications for all plunging ranulas,

whereas the extraoral approach is a relatively destructive

procedure, which may result in skin scarring, and is

unacceptable.

CONCLUSIONComparisons of clinical features and recurrence rates

among 3 patterns of ranula were documented, and the

results were analyzed. The plunging ranula has some

different clinical features from the oral or mixed ranula.

Fig 7. A mucus-containing space lined fibrous connective

tissue or granulation tissue with various sizes of vascular

lumen (hematoxylin-eosin stain, original magnification 3 33).

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The recurrence rates of ranula were not related to

swelling patterns and surgical approaches, but intimately

related to the methods of surgical procedure. We advise

the removal of the sublingual gland combined with

intraoral evacuation of the ranula be used regardless of

the clinical patterns of the lesion (oral, plunging, or

mixed ranula).

REFERENCES1. Catone GA, Merrill RG, Henny FA. Sublingual gland mucus-

escape phenomenon—treatment by excision of sublingual gland.J Oral Surg 1969;27:774-86.

2. Regezi JA, Sciubba JJ, editors. Oral pathology, clinicalpathologic correlations. 3rd ed. Philadelphia: WB SaundersCompany; 1999. p. 220-2.

3. Parekh D, Stewart M, Joseph C, Lawson HH. Plunging ranula: Areport of three cases and review of the literature. Br J Surg 1987;74:307-9.

4. Yoshimura Y, Obara S, Kondoh T, Naitoh SI. A comparison ofthree methods used for treatment of ranula. J Oral MaxillofacSurg 1995;53:280-2.

5. Lida S, Kogo M, Tominaga G, Matsuya T. Plunging ranula asa complication of intraoral removal of a submandibular sialolith.Brit J Oral Maxillofac Surg 2001;39:214-6.

6. Balakrishnan A, Ford GR, Bailey CM. Plunging ranula followingbilateral submandibular duct transposition. J Laryngol Otol 1991;105:667-9.

7. Crysdale WS, Mendelsohn JD, Conley S. Ranulas-mucoceles ofthe oral cavity: experience in 26 children. Laryngoscope 1988;98:296-8.

8. Batsakis JG, McClatchey KD. Cervical ranulas. Ann Otol RhinolLaryngol 1988;97(5 pt 1):561-2.

9. Anastassov GE, Haiavy J, Solodnik P, Lee H, Lumerman H.Submandibular gland mucocele: diagnosis and management. OralSurg Oral Med Oral Pathol Oral Radiol Endod 2000;89:59-63.

10. Coit WE, Hamsberger RH, Osborn AG, Smoker WR, StevensMH, Lufkin RB. Ranula and their mimics: CT evaluation.Radiology 1987;163:211-6.

11. Charnoff SK, Carter BL. Plunging ranula: CT diagnosis.Radiology 1986;158:467-8.

12. Baurmash HD. Marsupialization for treatment of oral ranula:a second look at the procedure. J Oral Maxillofac Surg 1992;50:1274-9.

13. Bridger AG, Carter P, Bridger GP. Plunging ranula: literaturereview and report of three cases. Aust NZ J Surg 1989;59:945-8.

14. de Visscher JG, van der Wal KG, de Vogel PL. The plungingranula: pathogenesis, diagnosis and management. J Craniomax-illofac Surg 1989;17:82-5.

15. Ichimura K, Ohta Y, Tayama N. Surgical management of theplunging ranula: a review of seven cases. J Laryngol Otol 1996;110:554-6.

16. Mizuno A, Yamaguchi K. The plunging ranula. Int J OralMaxillofac Surg 1993;22:113-5.

Reprint requests:

Yi-Fang Zhao, DDS, MSc

Department of Oral and Maxillofacial Surgery

College & Hospital of Stomatology

Wuhan University

237 LuoYu Road

Wuhan, People’s Republic of China 430079

[email protected]

mailto:[email protected]

clincal review of ranulas

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