LEUKOEDEMA: A REVIEW OF THE LITERATURE James L. Martin, DDS, MPH, D Litt Nashville, Tennessee
Leukoedema, a grayish-white lesion of the oral mucosa in humans, was once thought to be a probable precursor to leukoplakia. Clinical examination differentiates leukoedema from leukoplakia, lichen planus, white sponge nevus, and pathomimia morsicatio buccarum. Prevalence rates vary greatly in different countries and in different ethnic groups. For many years, leukoedema was alleged to occur only in adult populations until Martin and Crump' found this lesion in children and youth. There is a definite predilection for this lesion in black Americans. Although the etiology is unknown, it has been suggested that leukoedema develops in areas of local irritation. This article reviews the literature related to the prevalence of leukoedema and correlates the independent findings, which might pertain to its etiology. (J Nati Med Assoc. 1992;84:938-940.) Key words * leukoedema * oral mucosa * black Americans Leukoedema, a grayish-white lesion that characteristically appears on the buccal mucosa, was alleged to occur only in adult populations until Martin and Crump' found this lesion in children and youth. Leukoedema was first described by Sandstead and Lowe in 1953.2 They reported that leukoedema occurred as "patches" around lesions of leukoplakia or as "filmy" areas merging with leukoplakias and indicted leukoedema as a probable precursor to leukoplakia. In subsequent years, several investigators have attempted From the Department of Operative Dentistry, Meharry Medical College, Nashville, Tennessee. Requests for reprints should be addressed to Dr James L. Martin, Dept of Operative Dentistry, Meharry Medical College, 1005 D.B. Todd Blvd, Nashville, TN 37208. 938
to determine the etiology of this lesion.3-6 These independent studies were successful in correlating the clinical and histological aspects of leukoedema. Subsequently, all suspicions of malignancy were removed. The etiology of this abnormality remains unsolved, however. Clinical examination readily differentiates leukoedema from leukoplakia since there is no loss of pliability or flexibility of the involved tissues.7 In
addition, the tissues affected by leukoedema manifest an edematous state. Leukoedema is distinguished from lichen planus by stretching the buccal mucosa.8 Areas exhibiting leukoedema will either disappear or persist upon stretching, whereas lesions of lichen planus will become more pronounced. Leukoedema should also be differentiated from white sponge nevus and habitual cheek-biting (pathomimia morsicatio buccarum).9"10 White sponge nevus is a relatively uncommon lesion, and the buccal mucosa appears thickened and folded."l Superficial erosions that alternate with irregular white flakes are present in lesions of habitual cheek-biting whereas areas of leukoedema are usually smooth and grayish-white in coloration. Figure 1 shows leukoedema of the buccal mucosa in an adult male.
DISCUSSION Histologically, lesions of leukoedema exhibit hyperparakeratosis and are frequently elongated with irregular rete-pegs and intracellular edema of the malpighian layer. Increased mitoses, dyskeratosis, connective tissue atypia, and surface keratinization typical of cancerous lesions are not evident (Figure 2). Oral exfoliative cytology as a diagnostic aid in the diagnosis of leukoedema was first reported in 1969.12 Pap smears of the buccal mucosa showed leukoedematous cells that assumed irregular polyhedral shapes with a tendency to fold. The diameter of these cells ranged from 18 ,um to 60 rim. Vacuolation of the cytoplasm was a characteristic feature. There was a wide variation in nuclear size, JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 84, NO. 11
LEUKOEDEMA
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Figure 1. Severe leukoedema of the buccal mucosa in a 45 year-old black male. and the contained chromatin material was either irregularly condensed, eccentrically positioned, or completely absent. For many years, leukoedema was alleged to occur only in adults until Martin and Crumpl discovered this clinical entity in black children and youth. An incidence of 50.8% was observed. A definite relationship between leukoedema and poor oral hygiene was established. No relationship between leukoedema and its occurrence in siblings was observed. The prevalence of leukoedema varies in different ethnic groups and in different countries. Pindborg et al'3"4 observed this clinical entity in 96 of 10 000 Indians examined in Bombay, India and in 166 of 10 000 individuals examined in Lucknow, Uttar Pradesh, India. Martin'5 conducted a comprehensive survey of 4230 black patients ranging in age from newborn to 90 years during a 51/2 year period and found leukoedema in 58% of the patients examined. Leukoedema was most prevalent in adults in the 41- to 45-year-old age group. Sandstead and Lowe observed leukoedema in 43% of the white patients and 90% of the black patients comprising their survey.2 In Durocher's6 study, leukoedema was exhibited in 93% of the 430 dental patients examined in Geneva, Switzerland, while Mani16 reported an incidence of 4.3% among 57 518 industrial workers from India. In Van Wyk's survey, leukoedema was found in 24.4% of the black residents in the Cape Peninsula of South Africa.17 Although leukoedema has been alleged to be a variant of the normal epithelium,4'6 empirical evidence relates that leukoedema is an acquired condition caused by local irritation.3'18-21 Hammer and Villegas22 reported leukoedema in 76% of the Bolivian Indians who habitually chewed a coca leaf-lime mixture and lodged JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 84, NO. 11
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Leukoedema, a grayish-white lesion of the oral mucosa in humans, was once thought to be a probable precursor to leukoplakia. Clinical examination differentiates leukoedema from leukoplakia, lichen planus, white sponge nevus, and pathomimia morsicatio buccarum. Prevalence rates vary greatly in different countries and in different ethnic groups. For many years, leukoedema was alleged to occur only in adult populations until Martin and Crump' found this lesion in children and youth. There is a definite predilection for this lesion in black Americans. Although the etiology is unknown, it has been suggested that leukoedema develops in areas of local irritation. This article reviews the literature related to the prevalence of leukoedema and correlates the independent findings, which might pertain to its etiology. (J Nati Med Assoc. 1992;84:938-940.) Key words * leukoedema * oral mucosa * black Americans Leukoedema, a grayish-white lesion that characteristically appears on the buccal mucosa, was alleged to occur only in adult populations until Martin and Crump' found this lesion in children and youth. Leukoedema was first described by Sandstead and Lowe in 1953.2 They reported that leukoedema occurred as "patches" around lesions of leukoplakia or as "filmy" areas merging with leukoplakias and indicted leukoedema as a probable precursor to leukoplakia. In subsequent years, several investigators have attempted From the Department of Operative Dentistry, Meharry Medical College, Nashville, Tennessee. Requests for reprints should be addressed to Dr James L. Martin, Dept of Operative Dentistry, Meharry Medical College, 1005 D.B. Todd Blvd, Nashville, TN 37208. 938
to determine the etiology of this lesion.3-6 These independent studies were successful in correlating the clinical and histological aspects of leukoedema. Subsequently, all suspicions of malignancy were removed. The etiology of this abnormality remains unsolved, however. Clinical examination readily differentiates leukoedema from leukoplakia since there is no loss of pliability or flexibility of the involved tissues.7 In
addition, the tissues affected by leukoedema manifest an edematous state. Leukoedema is distinguished from lichen planus by stretching the buccal mucosa.8 Areas exhibiting leukoedema will either disappear or persist upon stretching, whereas lesions of lichen planus will become more pronounced. Leukoedema should also be differentiated from white sponge nevus and habitual cheek-biting (pathomimia morsicatio buccarum).9"10 White sponge nevus is a relatively uncommon lesion, and the buccal mucosa appears thickened and folded."l Superficial erosions that alternate with irregular white flakes are present in lesions of habitual cheek-biting whereas areas of leukoedema are usually smooth and grayish-white in coloration. Figure 1 shows leukoedema of the buccal mucosa in an adult male.
DISCUSSION Histologically, lesions of leukoedema exhibit hyperparakeratosis and are frequently elongated with irregular rete-pegs and intracellular edema of the malpighian layer. Increased mitoses, dyskeratosis, connective tissue atypia, and surface keratinization typical of cancerous lesions are not evident (Figure 2). Oral exfoliative cytology as a diagnostic aid in the diagnosis of leukoedema was first reported in 1969.12 Pap smears of the buccal mucosa showed leukoedematous cells that assumed irregular polyhedral shapes with a tendency to fold. The diameter of these cells ranged from 18 ,um to 60 rim. Vacuolation of the cytoplasm was a characteristic feature. There was a wide variation in nuclear size, JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 84, NO. 11
LEUKOEDEMA
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Figure 1. Severe leukoedema of the buccal mucosa in a 45 year-old black male. and the contained chromatin material was either irregularly condensed, eccentrically positioned, or completely absent. For many years, leukoedema was alleged to occur only in adults until Martin and Crumpl discovered this clinical entity in black children and youth. An incidence of 50.8% was observed. A definite relationship between leukoedema and poor oral hygiene was established. No relationship between leukoedema and its occurrence in siblings was observed. The prevalence of leukoedema varies in different ethnic groups and in different countries. Pindborg et al'3"4 observed this clinical entity in 96 of 10 000 Indians examined in Bombay, India and in 166 of 10 000 individuals examined in Lucknow, Uttar Pradesh, India. Martin'5 conducted a comprehensive survey of 4230 black patients ranging in age from newborn to 90 years during a 51/2 year period and found leukoedema in 58% of the patients examined. Leukoedema was most prevalent in adults in the 41- to 45-year-old age group. Sandstead and Lowe observed leukoedema in 43% of the white patients and 90% of the black patients comprising their survey.2 In Durocher's6 study, leukoedema was exhibited in 93% of the 430 dental patients examined in Geneva, Switzerland, while Mani16 reported an incidence of 4.3% among 57 518 industrial workers from India. In Van Wyk's survey, leukoedema was found in 24.4% of the black residents in the Cape Peninsula of South Africa.17 Although leukoedema has been alleged to be a variant of the normal epithelium,4'6 empirical evidence relates that leukoedema is an acquired condition caused by local irritation.3'18-21 Hammer and Villegas22 reported leukoedema in 76% of the Bolivian Indians who habitually chewed a coca leaf-lime mixture and lodged JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 84, NO. 11
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