Occurrence of focal epithelial hyperplasia among Amerindians in Ecuador

Int. J. Oral Surg. 1973: 2:45-53 (Key words: mouth diseases; Amerindians; epithelium)

Occurrence of focal epithelial hyperplasia among Amerindians in Ecuador FINN PRAETORIUS-CLAUSEN AND MIKKEL EMMERTSEN

Department o] Oral Pathology, Royal Dental College, and Dental Department, University Hospital, Copenhagen, Denmark The prevalence of focal epithelial hyperplasia in two small groups of Amerindians in Ecuador has been studied. All age groups were examined. Among 65 Cofanes Amerindians in Dureno, no cases of the disease could be diagnosed. At Huino, 125 Quichuas Amerindians were examined, and three cases of focal epithelial hyperplasia were found in two boys (9 and 12 years old) and a 15-year-old girl. Biopsies from all three patients verified the diagnosis. The prevalence among Quiehuas Amerindians was 2.4 %. ABSTRACT

- -

(Received/or publication 20 March, accepted I0 April 1973)

The term focal epithelial hyperplasia (FEH) was introduced by Archard, H e c k & Stanley1 to signify certain multiple, nodular elevations of the oral mucosa observed among Amerindians and Eskimos. The lesion has been described only on the oral mucosa. Studies of the point prevalence of focal epithelial hyperplasia have so far been made only in Amerindians and Eskimo populations12. The reason is probably that the amount of cases reported from all parts of the world has shown that the disorder is much more common in Amerindians and Eskimos than in any other population. The epidemiologic studies have shown considerable differences in the prevalences found in the examined populations of Amerindians and Eskimos. Among the Eskimos11 the prevalences found have been between

3 % and 36 %, most of them between 10 % and 20 %. The prevalences found in Amerindians are more moderate. Except for an unusually high prevalence of 34 % found among 160 school children in Venezuela15, all prevalences found4, ~,7, 9, is have been less than 3.5 %. As seen in Table 2 all age groups have been examined in only three of the Amerindian populations~,7,1s. In the four other groupsg, l~,ls the study has been limited to children, since for several years it was believed that the hyperplasias disappeared in grown-ups 9, Our knowledge about the geographical pathology of F E H is thus still incomplete, even in South America where a majority of the prevalence studies have been done. The purpose of the present study has been

46

PRAETORIUS-CLAUSEN AND EMMERTSEN

Putumayo

PACIFIC

J

OCEAN

.eno

Quit°e

Ambato

Guay~quil

ECUADOR

PERU

PERU Fig. 1. Map of Ecuador showing Huino and Dureno, where the present study took place.

to determine the prevalence of focal epithelial hyperplasia of all age groups in two different Amerindian populations in l'Oriente, Ecuador where no studies of this kind have been made previously.

Material and methods Indians from two different tribes living in the province of 1'Oriente, Ecuador have been examined: Quichuas Amerlndians from the jungle village Huino situated at the shore of the river

Huino, and Colanes Amerindians from the jungle village Dureno, situated at the river Aguarico (Fig. 1). The province of l'Oriente is a sparsely populated area of tropical rain forest east of the Andes mountains and of the capital Quito. The province borders on Colombia and Peru. Mestizos are the dominating population of the cities of l'Oriente, Amerindians are found primarily as different tribes in the jungle where they hunt monkeys, snakes, crocodiles, small rodents, and parrots, or live as small farmers cultivating bananas, platanos, peanuts, yucca, corn, and papaya. Two such Amerindian tribes are the Quichuas (syn. Yumbos or .&lamas) and the Cofanes. Quichuas

FOCAL E P I T H E L I A L HYPERPLASIA IN ECUADOR Amerindians make up a very numerous tribe, which is partly mLxed with other population groups. They are found predominantly in the mountain areas of Ecuador and Peru. When the Spaniards invaded the country from the north in the 16th century, several groups fled into the jungle and settled there around the rivers Napo and Coca. Most of the Quiehuas examined in the present study, however, moved into the jungle from the mountains in 1969. Cofanes Amerindians make up a considerably smaller tribe of about 500 individuals living in the area between Rio Coea and Rio Aguarico which borders on the state of Colombia (Putumayo). The Quiehuas and the Cofanes Amerindians speak different languages and have different cultures. The clinical examination of the oral mucosa of the population of Huino and Dureno was performed by one of the authors (M.E.) by means of wooden spatulas using direct sunlight as a source of light. Focal epithelial hyperplasias included all circumscribed, sessile, soft, elevated nodules either rounded and with a surface like the adjoining normal mucosa or with a flat whitish surface located on the oral mucosa of the lips, the buccal mucosa, the gingiva or alveolar process, the hard and soft palate, the floor of the mouth, and the tongue. The registration excluded elevations in the regions o~f the foliate and vallate papillae, the lower surface of the

47

tongue, and the floor of the mouth which could not be unambiguously distinguished from papillae and fimbriated folds. Very common small nodules at the insertion of the upper labial frenulum and at the beginning of the occlusal line in both commissures (cullingulum) were excluded as well, as were all acuminated, papillomatous, and fibroma-like elevations of the oral mueosa. Doubtful lesions were not registered. Information about age and possible history of disease was procured by means of an interpreter. Estimation of age is approximate in some cases but reasonably exact within a 10-year period. The intention was to examine the entire population of Huino and Dureno, but the result was highly dependent on the cooperation of the Amerindians. The Cofanes are not very open to strangers and thus only 65 % of them could be examined. The Quichuas Amerindians of I-Iuino were considerably more cooperative. There were about 145 persons living in the area, and a list of their names was available.

Results T h e distribution according to age a n d sex of t h e persons studied a m o n g t h e two A m e r i n d i a n populations is seen in T a b l e 1.

Table 1. Distribution according to age and sex of the populations examined for prevalence of focal epithelial hyperplasia Quichuas Indians from Huino, Ecuador Age in years

0-9

10-19

20-29

30-39

Women

23

13

6

9

Men

25

16

3

Total

48

29

9

40-49

50-59

60-69

Total

5

3

2

61

10

4

4

2

64

I9

9

7

4

125

40-49

50-59

60-69

Total

Co/ane~ Indians ]tom Dureno, Ecuador Age in years

0-9

10-19

20-29

30-39

Women

18

6

10

1

4

0

0

39

Men

12

4

3

3

4

0

0

26

Total

30

:[0

13

4

8

0

0

65

48

PRAETORIUS-CLAUSEN AND EMMERTSEN

No cases of focal epithelial hyperplasia were f o u n d among the 65 Cofanes Amerindians in Dureno. The reliability within 99 % limits8 is between 0.0 % and 7.8 %. About two-thirds of the persons examined are less than 22 years old; this age distribution is, however, not far from the age distribution of the entire population in Dureno, which numbers about 100 persons. Among the Quichuas of Huino, 125 persons (86 %) were examined and three cases of focal epithelial hyperplasia were diagnosed in a 9-year-old boy, a 12year-old boy, and a 15-year-old girl. The elder boy was a nephew of the girl. The 9year-old boy had about 10 small hyperplasias located on the lower lip and the 12year-old boy had three hyperplasias located on the lower lip. Before the examination of the population he had had a tooth extracted

by the examiner, and at that time the lesions were not present. A week after they were diagnosed the boy was re-examined and the hyperplasias were found to have grown to about double the size within that week. The 15-year-old aunt (Fig. 2) of this bey had 21 hyperplasias; 5 were located on the upper lip, 10 on the lower lip, 1 on the right commissure and 5 on the left commissure. She reported that the hyperplasias had started about a month earlier when two lesions appeared. She had noticed pain every time a hyperplasia had developed. Although the size and n u m b e r varied, the lesions were uniform in appearance. Most of them were sessile, flat, soft, papular elevations with the same coloring as the surrounding oral mucosa. The prevalence of focal epithelial hyperplasia among the examined Quichuas Amer-

Fig. 2. Focal epithelial hyperplasia in a 15-year-old girl of the Quichuas Amerindians in Huino, Ecuador. She had 21 hyperplaslas, 5 located on the upper lip, 10 on the lower lip, 1 on the right commissure, and 5 on the left commissure. Growth of the hyperplasias started when two lesions appeared about a month before this photo was taken.

FOCAL EPITHELIAL HYPERPLASIA IN ECUADOR iii":~,?:, ,,'~ ,:~,, , .....

! ",

,

'

" ,

::

, ,

:-

:'

"

49

,

'

,

:

i,/

:

Fig. 3. Section of one of the lesions from the lower lip shown in Fig. 1. Epithelial hyperplasia with acanthosis and increased cellular density is seen. The surface is slightly parakeratotic. X 60.

indians in Huino is 2.4 %. Within 99 % limitss this represents between 0 . 3 1 % and

Discussion

8.5 %.

Since 1956, cases of focal epithelial hyperplasia occurring in Amerindians from Central and South America have been published from several countries: BoliviaZ,10, Brazil~,18 Colombia4,~&9, E1 Salvador t8, G u a temalatZ,17,1a, Mexicol~, ParaguayT, Peru :2,7,t4, and Venezuela~. The results of the examination of the cases in the present study correspond well, clinically as well as histologically, to the results published from studies of the A m e r indians mentioned above. All three cases of focal epithelial hyperplasia diagnosed among the Quichuas in Ecuador were less than 20 years old. This is in agreement with previous findings in Amerindians and in Mestizos in Central and South America, where only very few cases in grown-ups have been described. Since,

Biopsies were taken from all three cases of focal epithelial hyperplasia and in all cases (Figs. 3 and 4) the histologic examination showed characteristic features of epithelial hyperplasia with acanthosis, elongation and anastomosing of rete ridges, increased cellular density of epithelium, enlarged epithelial nuclei and multinucleated cells. Increased mitotic activity was seen in the basal layer and cells with double nuclei were a frequent finding. Typical ceil degenerations seen in cases from Eskimos and Caucasians 11 could not be found in the present material. Liquefaction degeneration of epithelial basal cells could not be demonstrated, and dyskeratosis and epithelial dysplasia were not seen.

50

PRAETORIUS-CLAUSEN AND EMMERTSEN

Fig. 4. Higher magnification of another section of the same lesion showing increased cellular density, hyperchromatic nuclei, and an increased number of mitotic figures in basal - and prickle cell layers. Many cells with double nuclei are seen. X 600.

however, the relative n u m b e r of persons in the older age groups is small i n these populations, no statistically significant difference between the prevalence of I~EH in persons younger and older than 20 years could be found. A m o n g the Quichuas three cases of F E H were diagnosed in 77 persons younger than 20 years of age and no cases in 48 persons older than 20 years. The 99 % limits are 0 . 4 4 % - 1 3 . 5 4 % and 0 % 10.45 %, respectively. Apart from Fischman's study in Paraguay, where only one case of F E H was found among 8,569 persons, other studies of A m e r i n d i a n s inctuding all age groups have been made on a limited n u m b e r of persons. I n Colombia6 two eases of F E H were found in 75 persons, and in Mato Grosso, Brazil seven cases were f o u n d in 206 persons iS. This m a y explain the apparent difference

in occurrence of F E H in grown-ups among the Indians and the Eskimos ~t. The prevalence of focal epithelial hyperplasia of 2.4 % found among the Quichuas corresponds well to the prevalences of this disease found among other Amerindian populations in Central and South America~,6,7,9,15,18. All but one of the prevalences have been less than 3.5 % (Table 2). No significant difference could be demonstrated, however, between the findings in the two groups of Indians in the present study. Within 99 % limits8 the 0 % among the Cofanes represents 0.0 % - 7 . 8 % and the 2.4 % among the Quichuas represent 0.3 % - 8.5 %. The different prevalenees found in the two groups m a y thus not be representative, since it might easily be explained as a random finding because of the relatively small groups studied.

F O C A L EPITHELIAL H Y P E R P L A S I A IN E C U A D O R

51

cq ~O

'~"

¢q

r-t

~4

oq

¢5

oq

cq

°

c.i

O

g ,...,

<

<

t

<

g ¢1

-<

~D

In

O c'q

g

",O

o~

O 0a

U

0 e~

O

o O

L~ O o ,.t::l

O

(..)

g

¢..,

I:::I

:

"N

e~ °~

c~

;z

(y

•,:a"

0'3 ,O

0o

%

N

<

U

o

~:

',D

¢.)

52

PRAETORIUS-CLAUSEN AND EMMERTSEN

Since histologic examination verified the diagnoses in the three cases found among the Quichuas, and the tribe numbered 145 persons, the point prevalence of F E H in this study can be estimated not to be less than 2 . 1 % . It is unlikely that the results in the present study are caused by the selection of the material. No selection has taken place other than that caused by lack of cooperation and by the absence of Indians working temporarily in another area. Although the selection may be a source of error, it is very unlikely that any person refused examination because of the presence of focal epithelial hyperplasia. About 65 % of the Cofanes could be studied and 86 % of the Quichuas. In both cases about 60 % of the population were less than 20 years old, which corresponds well with the age distribution of the entire population in both areas studied. In one of the cases reported in the present study, the lesions were noted to develop within a relatively short time. Similar observations have been made among the Eskimos in GreenlandlL Many suggestions concerning the etiology of focal epithelial hyperplasia have been given in the literature. Local irritating factors like tobacco, electrogalvanic currents between amalgam fillings, vitamin A deficiency, and other nutritional factors have been suggested. So have genetic factors because of familial occurrence. It is striking that the lesions tend to develop in regions of the oral mucosa which are exposed most often to minor traumas. Thus the lips, the margins of the tongue and the occlusal line of the buccal mucosa are the common sites. It is as yet unknown, however, whether especiatly hard food can promote the development of the lesions. Familial occurrence has been described by several authors1,9,11 and was observed in the present study as well. Although this

could speak for a genetic factor, it would also apply if the disease was of an infectious nature only is. Evidence of a viral etiology has been found based on microscopic, electron microscopic and immunofiuorescence examinationsll. Possible influence of a genetic factor as well, however, cannot be excluded. Acknowledgment - Partly supported by a grant

(5/2-41[69) from the Danish Medical Research Council.

References 1. ARCHARD,H. O., J'TECK,J. W. ~¢ STANLEY, H, R.: Focal epithelial hyperplasia: A n unusual oral mucosal lesion found in Indian children. Oral Surg. 1965: 20: 201-212.

2. BELTRAN,R.: Penal sobre diagnostico oral. VI. Congreso Nacional de Odontologia, and II. Congreso International de Estomatologia del Peru, Lima, Peru. Nov. 21, 1966. 3. D~cmea, W. G. & GtrZM~N, M. N. DE: Focal epithelial hyperplasia. Report of four cases in Mestizos from Cochabamba, Bolivia. Oral Surg. 1969: 27: 15-19. 4. ESTRADA,L,: Aporte al estudio odontologleo de los Indios. Her. Dent. 1956: 2: 5-11. 5. ES'rR^OA,L : Informe preliminar sobre algunos aspectos odontol6gicos de los Indios Caramanta. Bol. Inst. Antropol. Univ. Antioquia 1956: 1: 319. 6. ES'rl~DA, L.: Estudio m6dico y odontol6gico de los Indios Katios del Choco. Temas Odontol. 1960: 7: 198-210. 7. FlSCHMAN,S.L.: Focal epithelial hyperplasic. Case reports from Paraguay and Peru. Oral Surg. 1969: 28: 389-393. 8. DOCUMENTA GEIOY: Scientific Tables. 7th ed., J.R. Geigy, Basel 1970, p. 85-103. 9. Gorcmz, A., CALLt~,C., ARCILA,G. • PINDBORG, L J.: Focal epithelial hyperplasia in a half-breed family of Colombians. I. Am. Dent. Assoc. 1969: 79: 663-667, 10. HANKS,C, T., FlSCHMAN,S.L. & DE GUZMAN,A.N.: Focal epithelial hyperplasia. A light and electron microscopic study of one case. Oral Surg. 1972: 33: 934---943. ]i. PR.,ETORIUS-CLAUSEN,F.: Rare oral viral disorders (molluscum contagiosum, local-

PRAETORIUS-CLAUSEN AND EMMERTSEN ized keratoacanthoma, verrucae, condyloma acuminatum, and focal epithelial hyper~ plasia). Oral Surg. 1972: 34: 604-618. 12. PamTORIUs-CL~,OSEI%F.: Geographical aspects of oral focal epithelial hyperplasia. Path. et Microbiol. 1973: 39: 204-213. 13. l~YnS, D. G.: Verruga de la cavidad oral. Rev. Cal. M~d. Guatem. 1962: 13: 223226. 14. ROSSEL,E.: Estudio clinico de lesiones en mucosa labial en el bajo Amazonas. VI. Congreso Nacional de Odontologia and II. Congreso Internacional de Estomatologia del Peru, Lima, Peru. Nov. 22, 1966.

Address: F. Prtetorius-Clausen Department of Oral Pathology Royal Dental College 4 Universitetsparken DK-2100 Copenhagen 0 Denmark

53

15. SoNmRA,A. & Folqsnc^, N.: Sobre une lesi6n de la mucosa oral en los ninos Indios de la Misi6n Los Angeles del Tokuko. Venez. Odontol. 1964: 29: 109-119. 16. TAN,K.N., MEDAK,H., Col-teN,L. & BImLAI~OW,P.: Focal epithelial hyperplasia in a Mexican Indian. Arch. Dermatol. 1969: 100: 474-477. 17. VASQtmZ,A. M.: Focal epithelial hyperplasia in a Guatemalan highland Indian community. Rev. Guatem. Estomatol. 1971: 1: 55-62. 18. WITKOP,C.J. & N1SWANDER,I.D.: Focal epithelial hyperplasia in Central and South American Indians and Ladinos. Oral Surg. 1965: 20: 213-217.