Quick Review for Patients
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Leukoedema is a common developmental alteration of the oral mucosa which appears to be a simple variation of normal anatomy. When the most mild cases are included, it is seen in almost 90% of adult blacks and half of adult whites, although it presents as a much less pronounced alteration in whites (prevalence rate: 3/1,000 white adults, see Table 1). Tobacco smoking and chewing has been shown to enhance the whiteness and size of the lesion but most cases are so subtle that they are not formally diagnosed. Similar mucosal changes have been reported on vaginal and laryngeal mucosa.
Leukoedema presents most typically as an asymptomatic, bilateral, whitish gray, semitransparent macule of the buccal mucosa (Figures 1 & 2). Occasional patients show fine grooves or folds crisscrossing the macule in a delicate lace-like pattern. This mucosal change may begin as early as 3-5 years of age, but is not usually noticeable until adolescence. By the end of the teenage years, 50% of black children demonstrate the altered mucosa.
The opalescent macule is usually poorly demarcated
from surrounding mucosa and is occasionally seen on the soft palate and oral
floor (Figure 3). When the cheeks are stretched outward, the leukoedema typically
Pathology and Differential Diagnosis
Leukoedema is characterized by a variable intracellular edema of the superficial half of the epithelium (Figures 4 & 5). The vacuolated cells are large and often have pyknotic nuclei. They may extend to the basal layer and may cluster into inverted wedge-shaped regions separated by normal spinous epithelial cells (Figure 6). The epithelium is hyperplastic and rete ridges are often broad and elongated. Parakeratosis is commonly seen but is not pronounced unless there has been chronic trauma.
Intracellular edema is characteristic of several other oral lesions, many of which may be found on the buccal mucosa: smokeless tobacco keratosis, frictional keratosis (chronic cheek bite keratosis), white sponge nevus and Witkop's disease. The identification of etiologic habits will greatly ease the difficulty of establishing a final diagnosis for smokeless tobacco keratosis and frictional keratosis. Microscopically, these typically present with a more pronounced surface keratosis and have scattered chronic inflammatory cells within underlying stroma.
Since leukoedema and white sponge nevus both have innocuous onsets in the childhood and teenage years, it may be impossible to distinguish between them except by the clinical "stretch test." The nevus will remain visible when the affected mucosa is stretched, while leukoedema will disappear. Hereditary benign intraepithelial dyskeratosis (HBID, Witkop's disease) also shows pronounced intracellular edema, but can be distinguished from the others by the scattered presence in the spinous layer of individually keratinized cells. The reader is referred to the following section pertaining to white sponge nevus for a more thorough discussion of the differential diagnosis of these lesions.
Treatment and Prognosis
No treatment is necessary for leukoedema. It has no malignant potential and does not change significantly after 25-30 years of patient age. Should the affected individual stop using tobacco products, the lesion will likely become less pronounced.
References (Chronologic Order)
Note: Click on underlined author's names for additional detail.
Neville BW, Damm DD, Allen CM, Bouquot JE. Oral and maxillofacial pathology. Philadelphia, W. B. Saunders; 1995.
Elder D, Elenitsas R, Jaworsky C, Johnson B Jr. Lever's Histopathology of the skin, 8th edition. Philadelphia; Lippincott-Raven, 1997.
Sapp JP, Eversole LR, Wysocki GP. Contemporary oral and maxillofacial pathology. Mosby; St. Louis, 1997.
Odell EW, Morgan PR. Biopsy pathology of the oral tissues. London; Chapman & hall Medical, 1998.
Archard HO, et al. Leukoedema of the human oral mucosa. Oral Surg Oral Med Oral Pathol 1968; 25:717-728.
Martin JL. Leukoedema: a review of the literature. J Natl Med Assoc 1992; 84:938-940.
Hernandez-Martin A, et al. Diffuse whitening of the oral mucosa in a child. Pediatr Dermatol 1997; 14:316-320.
Martin JL. Leukoedema: an epidemiological study in white and African Americans. J Tenn Dent Assoc 1997; 77:18-21.
Table 1: Gender-specific prevalence rates per 1,000 population for selected oral masses and surface alterations in U.S. adults, ranked by total frequency. Modified from Bouquot JE. Common oral lesions found during a mass screening examination. J Am Dent Assoc 1986; 112:50-57, and Bouquot JE, Gundlach KKH. Oral exophytic lesions in 23,616 white Americans over 35 years of age. Oral Surg Oral Med Oral Pathol 1986; 62:284-291.
* total examined population = 23,616 adults over 35 years of age
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