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

ABSTRACT - - 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 Amer- indians 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 %.

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

The term focal epithelial hyperplasia (FEH) was introduced by Archard, Heck & Stan- ley1 to signify certain multiple, nodular ele- vations 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 popula- tions12. 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 Amer- indians 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 Amer- indians 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 Amer- indian populations~,7,1s. In the four other groupsg, l~,ls the study has been limited to children, since for several years it was be- lieved 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

PACIFIC J OCEAN Quit°e

Putumayo

.eno

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 epithel- ial hyperplasia of all age groups in two dif- ferent 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 ex- amined: 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 Co- lombia and Peru. Mestizos are the dominating population of the cities of l'Oriente, Amer- indians 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. Yum- bos or .&lamas) and the Cofanes. Quichuas

FOCAL EPITHELIAL HYPERPLASIA IN ECUADOR 47

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 f rom the mountains in 1969. Cofanes Amerindians make up a considerably smaller tr ibe of about 500 individuals living in the area between Rio Coea and Rio Agua- rico 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 sun- light as a source of light.

Focal epithelial hyperplasias included all circumscribed, sessile, soft, elevated nodules either rounded and with a surface like the ad- joining normal mucosa or with a flat whitish surface located on the oral mucosa of the lips, the buccal mucosa, the gingiva or alveolar pro- cess, the hard and soft palate, the floor of the mouth, and the tongue. The registration ex- cluded elevations in the regions o~f the foliate and vallate papillae, the lower surface of the

tongue, and the floor of the mouth which could not be unambiguously distinguished from pa- pillae 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 pop- ulation 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 The dis t r ibut ion according to age and sex

of the persons studied among the two Amer-

indian popula t ions is seen in Table 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 40-49 50-59 60-69 Total

Women 23 13 6 9 5 3 2 61

Men 25 16 3 10 4 4 2 64

Total 48 29 9 I9 9 7 4 125

Co/ane~ Indians ]tom Dureno, Ecuador

Age in years 0-9 10-19 20-29 30-39 40-49 50-59 60-69 Total

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 found among the 65 Cofanes Amer- indians in Dureno.

The reliability within 99 % limits8 is be- tween 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 12- year-old boy, and a 15-year-old girl. The elder boy was a nephew of the girl. The 9- year-old boy had about 10 small hyper- plasias located on the lower lip and the 12- year-old boy had three hyperplasias located on the lower lip. Before the examination of the populat ion 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 com- missure and 5 on the left commissure. She reported that the hyperplasias had started about a month earlier when two lesions ap- peared. She had noticed pain every time a hyperplasia had developed.

Although the size and number varied, the lesions were uniform in appearance. Most of them were sessile, flat, soft, papular ele- vations with the same coloring as the sur- rounding oral mucosa.

The prevalence of focal epithelial hyper- plasia among the examined Quichuas Amer-

Fig. 2. Focal epithelial hy- perplasia in a 15-year-old girl of the Quichuas Amer- indians 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 ta- ken.

FOCAL EPITHELIAL HYPERPLASIA IN ECUADOR 49

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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 % limits s this represents between 0 .31% and 8.5 %.

Biopsies were taken from all three cases of focal epithelial hyperplasia and in all cases (Figs. 3 and 4) the histologic examin- ation showed characteristic features of epith- elial hyperplasia with acanthosis, elongation and anastomosing of rete ridges, increased cellular density of epithelium, enlarged epithelial nuclei and multinucleated cells. In- creased 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 Cauca- sians 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.

Discussion

Since 1956, cases of focal epithelial hyper- plasia occurring in Amerindians from Cen- tral and South America have been published from several countries: BoliviaZ,10, Bra- zil~,18 Colombia4,~&9, E1 Salvador t8, Gua- temalatZ,17,1a, Mexicol~, ParaguayT, Pe- ru :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 Amer- indians mentioned above.

All three cases of focal epithelial hyper- plasia 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,

50 PRAETORIUS-CLAUSEN AND EMMERTSEN

Fig. 4. Higher magnification of another section of the same lesion showing increased cellular den- sity, 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 number of persons in the older age groups is small in these pop- ulations, no statistically significant differ- ence between the prevalence of I~EH in per- sons younger and older than 20 years could be found. Among 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 Para- guay, where only one case of F E H was found among 8,569 persons, other studies of Amerindians inctuding all age groups have been made on a limited number of persons. In Colombia 6 two eases of FEH were found in 75 persons, and in Mato Grosso, Brazil seven cases were found in 206 persons iS.

This may explain the apparent difference

in occurrence of FEH in grown-ups among the Indians and the Eskimos ~t.

The prevalence of focal epithelial hyper- plasia of 2.4 % found among the Quichuas corresponds well to the prevalences of this disease found among other Amerindian populations in Central and South Ameri- ca~,6,7,9,15,18. All but one of the prevalences have been less than 3.5 % (Table 2).

No significant difference could be demon- strated, however, between the findings in the two groups of Indians in the present study. Within 99 % limits 8 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 may thus not be representative, since it might easily be ex- plained as a random finding because of the relatively small groups studied.

FOCAL EPITHELIAL HYPERPLASIA IN E C U A D O R 51

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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 ex- amination 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 dis- tribution of the entire population in both areas studied.

In one of the cases reported in the pre- sent study, the lesions were noted to develop within a relatively short time. Similar ob- servations have been made among the Es- kimos in GreenlandlL

Many suggestions concerning the etiology of focal epithelial hyperplasia have been given in the literature. Local irritating fac- tors like tobacco, electrogalvanic currents between amalgam fillings, vitamin A de- ficiency, and other nutritional factors have been suggested. So have genetic factors be- cause of familial occurrence.

It is striking that the lesions tend to de- velop 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. I t 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 infec- tious nature only is.

Evidence of a viral etiology has been found based on microscopic, electron micro- scopic and immunofiuorescence examina- tionsll.

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: An un- usual 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 Estoma- tologia 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 odontolog- leo de los Indios. Her. Dent. 1956: 2: 5-11.

5. ES'rR^OA, L : Informe preliminar sobre al- gunos aspectos odontol6gicos de los In- dios Caramanta. Bol. Inst. Antropol. Univ. Antioquia 1956: 1: 319.

6. ES'rl~DA, L.: Estudio m6dico y odontol6- gico de los Indios Katios del Choco. Temas Odontol. 1960: 7: 198-210.

7. FlSCHMAN, S.L.: Focal epithelial hyperpla- sic. 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. • PIND- BORG, 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 GUZ- MAN, 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 53

ized keratoacanthoma, verrucae, condyloma acuminatum, and focal epithelial hyper~ plasia). Oral Surg. 1972: 34: 604-618.

12. PamTORIUs-CL~,OSEI% F.: Geographical as- pects 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: 223- 226.

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.

15. SoNmRA, A. & Folqsnc^, N.: Sobre une le- si6n 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. & BIm- LAI~OW, P.: Focal epithelial hyperplasia in a Mexican Indian. Arch. Dermatol. 1969: 100: 474-477.

17. VASQtmZ, A. M.: Focal epithelial hyperpla- sia in a Guatemalan highland Indian com- munity. 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.

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