Int. ]. Oral Surg. 1978: 7:162-166

(Key words: surgery, oral; liporna; benign tumor o] oral tissue)

Lipomas of the oral cavity

HALLVARD VINDENES

Department oJ Oral Surgery, University of Bergen, Department of Oral and Maxillofacial Surgery, Haukeland Sykehus, Bergen, Norway

ABSTRACT - - The clinical and histopathologic characteristics of oral lipomas are reviewed. A series of six patients undergoing surgical treatment for oral lipomas at the University of Bergen, Department of Oral Surgery during the period 1969-1976 is presented. The char- acteristics o~ the six tumors are described and the findings compared with those of previously reported cases.

(Received Jot" publication 11 April, accepted 7 July 1977)

Lipomas are slowly growing, encapsulated tumors of soft, fatty tissue. They are freely mobile in relation to surrounding tissues. Clinically, oral lipomas have a semilucent yellow color. A sensation of fluctuation may be recognized in these tumors, de- pending on the quantity and distributions of fibrous tissue and the tumor's depth of location in the tissue. Oral lipomas often have concentrations of capillary vessels in the overlying mucosa.

Macroscopically as well as histologically cross sections of the tumor resemble those of normal fat tissues. The cells are arranged in irregular layers separated by variable quantities of connecting tissue, containing vacuoles of neutral fat. Their nuclei are peripherally situated, flattened and contain central chromatin material. The tumor is enclosed by a thin connective tissue cap- sula, lobulated by septa and containing a variable amount of connective tissue ~~

The metabolism of lipoma differs from that of other fatty tissues of the body. Thus, during starvation conditions, it has been shown that the fat of lipoma is not utilized for energy production as are other fat tissues 3. The fatty tissue of lipoma com- bines acetate to fatty acids more rapidly than other fatty tissues in the same in- dividual. This points to an alteration in fat metabolism as a major factor in the etio- logy of lipoma 9.

As early as 1887, GRoscn z~ reported 716 cases of lipoma, none of which occurred in the mouth. In 1934 of 460 lipomas re- ported, only three occurred in the mouth 1~ In a survey o,f over 1,822 benign oral tu- mors, only four lipomas were foundL BERNIER ~ reported that lipomas account for 1 % of all benign tumors in the oral tissues It was found s that 4.4 % of benign oral tumors consisted of lipoma. HATZlOTIS v~ reviewed 145 cases of oral lipomas from

LIPOMAS OF THE ORAL CAVITY

Table 1. Oral lipomas: Patients' sex, age and preoperative diagnosis

163

Patient Sex Age Preoperative diagnosis

1 F 71 Mucocele 2 M 51 Fibroma buccae 3 F 67 Tumour labii inferior 4 F 53 Tumour buccae 5 M 13 Tumoar labii superior 6 M 68 Lipoma

2 = 53.8 years

the l i terature of the per iod 31945-1967,

Dur ing the period 1948-1968, 96 cases of

oral l ipoma were described in Anglo- Amer ican l i terature ~, while only seven new

cases were reported in the per iod 1967- 197311 .

L ipomas occur in all races ~ and the total incidence for the body as a whole is higher

in women than in men~~ I8. However , con-

sidering oral l ipomas only, a higher in- cidence among men than among women

has been found .3. In a series of 96 oral

l ipomas, 55 occurred in men and 41 in wo-

men ~ in a repor t of 24 cases ~, the same

incidence was found among men and wo-

men. Lipomas occur in all age groups, but oral

l ipomas are seen m o r e f requent ly after

40 years of age *a. One case has been re-

por ted in a newborn baby ~9, another in an

87-year-old w o m a n 1~.

The published mater ial concerning oral

l ipomas has shown a variable distribution

of these tumors, but approximate ly half

were related to the buccal mucosa. The

remainder were variously distributed in

the tongue, f loor of the mouth, lips, palate

and gingiva.

Material P A T I E N T S The patients' sex, age (at the time of surgery) and preoperative diagnosis are recorded in Table 1. The time interval from when the pa- tient noticed the swelling until surgery and the reason ,for admission are recorded in Table 2, The localization and size of tumor are sum- marized in Table 3.

During the period August 1969 - October 1976, six oral lipomas were surgically removed at the Department of Oral Surgery, University of Bergen, Department of OraI and Maxillo- facial Surgery, Haukeland Hospital. Four of these were diagnosed and removed within a period of 6 months (Apr i l - October 1976).

Results All of these tumors surgically r emoved

were encapsulated and the postoperat ive

Table 2. Oral lipomas: Observation time and reason for admission

Patient Observation time Reason ~or admission

1 ~4 days Growing quickly 2 30 years Routine dental examination 3 3 years Routine dental examination 4 3 years Growing slowly 5 4 months Growing quickly 6 30 years Fitting of dentures

164 VINDENES

Table 3. Oral lipomas: Oral localization and size of tumor

Patient Localization Size

1 Left cheek 15 • 15 Z 10mm 2 Right cheek 10 X 10 • 15 mm 3 Lower lip, right Spherical diam. 5 mm 4 Left cheek 25 • 15 • 10mm 5 Upper lip, right 40 X 20 • ~0 mm 6 Floor of mouth region-5 15 • 7 )< 5 mm

course in all patients was uncomplicated (Fig. 1). There has been no recurrence of tumor to the present date. Radiographic examination in one patient revealed that the tumor was situated in the floor of the mouth (Figs. 2, 3). A definite histopatho- logic diagnosis of lipoma was established in every case (The Gade Institute, Depart- ment of Pathology, University of Bergen).

Discussion Lipomas o~f the oral cavity are rarely re- ported. Recent investications, however, show that they occur more frequently than previously recognized6, 8. SHAPIRO 1~ stated that lipomas were recently being discovered more frequently, and the present material is in agreement with these observations. The accepted treatment is surgical excision

and biopsy. Recurrences are rarely re- ported. No recurrences have been seen to date in the cases presented in this article.

Malignant change in a lipoma has been reported only once and that case is poorIy documented 7. There is also one description of a lipofibroma os the pharynx and larynx which was histologically benign on several recurrences, but eventually, after 14 years, became malignant 1~.

The etiology of lipomas is obscure even though it is stated that the metabolism of the tumor is different from that of normal fatty tissue.

One of our patients suggested trauma as an etiologic factor in the development of the tumor. After crown preparation of a mandibular premolar, the patient observed a swelling in the floor of the mouth. The patient was aware of but not bothered by

i~ �84 j /

Fig. l . Lipoma of right upper lip in a 13-year- old boy. Incision through mucosa reveals typi~ cal appearance of lipoma.

Fig. 2. Sublingual lipoma in a 68-year-old man. The typical appearance of fat tissues is visible through the oral mucosa (indicated by arrows).

LIPOMAS OF THE ORAL CAVITY 165

f : 2'

Fig. 3. Radiographic examination of sublingual space in a 68-year-old man (same patient as Fig. 2). The arrows indicate the sublingual lipoma.

the tumor for 30 years before surgical re-

moval. Even though t r auma does not seem

to cause this type of tumor , it may make

the patient aware of an already existing

t u m o r Y

It is of further interest to note that three

tumors were located in the l inea alba of the cheeks. The distribution of tumors in

the present material in which half are located in the cheeks agrees with the ten-

dency reported previously. In two patients the l ipomas were first discovered by rou-

tine dental examinat ion. These observations agree with those found by C~,NNEL et alfi

in several of their patients. In this mater ial only one tumor was pre-

operat ively diagnosed as a l ipoma. This may

be due to the other f ive tumors being

located deep in the oral tissues.

The present examinat ion also reveals

that pat ients with oral l ipomas often post- pone their medical t rea tment because their

clinical symptoms can be disregarded. The

prognosis is good, however , in spite of

delayed diagnosis and treatment .

References 1. BERNmR, 1. L.: Survey of pathologic speci-

mens from the oral regions seen at the

Army Institute of Pathology during World War lI. Mil. Surg. 1947: 101: 362--375.

2. BERNIER, J, L.: The management of oral disease, 2nd ed. C. V. Mosby, St. Louis 1959, pp. 770-781.

3. BOYD, W.: A textbook of pathology, 8th ed. Lea & Febiger, Philadelphia 1970, p. 291.

4. BRASF1ELD, R. D. & DAS GUPTA, T. K.: Soft tissue tumors: benign tumors of adi- pose tissue. Cancer 1969: 19: 3-7.

5. BURZYNSKI, N. J., SIGMAN, M. D. & MAR- TIN, T. H.: Lipolna of the oral cavity: literature review and case report. J. Oral Med. 197]: 26: 37-39.

6. CANNEL, H , LANGDON, J. D., PATEL, M. F. & RAVlmS, A. D.: Lipomata in oral tissues. J. Maxillo/ac. Surg. 1976: 4: 116-119.

7. CORREIA, P. DE CASTRO: Recurrent lipoma of floor of mouth. Rev. Paul. Med. ]956: 49: 281-286.

8. DOCKERTY, M. B., PARKHILL, E. M., DAH- LIN, D. C., WOOLNER, L. B., SOULE, E. H. & HARriSON, E. G.: Tumors of the oral cavity and pharynx. Atlas o/ tumor pa- thology. Armed Forces Institute of Pa- thology, Washington, D.C. 1968, pp. 155, 169, 189-/9i, 263.

9. GELLHORN, A. & MARKS, P. A.: The com- position and biosynthesis of lipids in hu- man adipose tissues. J. C[in. Invest. i961: 40: 925-932.

10. GESCmCTER, C. F.: Lipoid tumors. Am. J. Cancer 1943: 21: 617-641.

11. GREER, R. O. & RICHARDSON, J. F.: The nature of lipomas and their significance in the oral cavity. Oral Surg, 1973: 36: 551- 557,

12. GROSCH, ].: Studien fiber das Lipom. Dtsch. Z. Chir. 1887: 26: 307-382.

13. HATZIOTIS, J. C.; Lipoma of the oral cavity. Oral Surg. 1971: 31: 511-524,

14. KAPUR, T. R.: Recurrent lipomata of the larynx and the pharynx with late malig- nant change. J. Lary~zgol. Otol. 1968: 82: 716-768.

15. NOCENTINL P.: II lipoma e l'iperplasia pseudolipomatosa della lingua nella loro discriminazione mediante ricerche istolo- giche sullo sviluppo e la distribuzione del tessuto adiposo linguale. Arch. Vecchi Anat. Patol. 1949: 13: 325-340.

16. SHAFER, W. G., HINE, M. K. & LEVY, B. M.: A textbook o/ oral pathology, 3rd ed. W.B. Saunders, Philadelphia 1974, pp. 140-141.

166 VINDENES

17. SHAPIaO, D. N.: Lipoma of the oral cavity. Oral Surg. 1969: 27: 871-876.

18. WAKELY, C. & SOMERVILLE, P.: Lipomas. Lancet 1952: if: 995-999.

19. YOSmMtmA, Y., MIYAGI, K., SHOJU, M., MATSUMURA, T.~ KAWAKATSU, K. ~ YOSHI- OKA, W.: Lipoma in the infant and child: report of cases. J. Oral Surg. 1972: 30: 690-693.

Address:

Department of Oral and Maxillofacial Surgery Haukeland Sykehz~s Bergen Norway