It has been suggested that leukoplakia is an unhelpful term since there is so much inconsistency surrounding its use, and some clinicians now avoid using it at all. Biopsy
Tissue biopsy is usually indicated to rule out other causes of white patches and also to enable a detailed histologic examination to grade the presence of any epithelial dysplasia. This is an indicator of malignant potential and usually determines the management and recall interval. The sites of a leukoplakia lesion that are preferentially biopsied are the areas that show induration (hardening) and erythroplasia (redness), and erosive or ulcerated areas. These areas are more likely to show any dysplasia than homogeneous white areas.Brush biopsy/exfoliative cytology is an alternative to incisional biopsy, where a stiff brush is scraped against the lining of the mouth to remove a sample of cells. This is then made into a smear which can be examined microscopically. Sometimes the biopsy site can be selected with adjunct methods which aim to highlight areas of dysplasia. Toluidine blue staining, where the dye is preferentially retained by dysplastic tissue, is sometimes used, but there is high false positive rate. Other methods involve the use of luminescence, relying on either the property of normal autoflorescent molecules in mucosa such as collagen and keratin which is lost from areas of dysplasia or carcinoma under blue light or by initially staining of the mucosa with toluidine blue or dilute acetic acid and examination under white light. Histologic appearance
Leukoplakia has a wide range of possible histologic appearances.
The symptoms may include frequency, suprapubic pain (pain felt above the pubis), hematuria (blood in the urine), dysuria (difficult urination or pain during urination), urgency, and urge incontinence. The white lesion may be seen during cystoscopy, where it appears as a whitish-gray or yellow lesion, on a background of inflamed urothelium and there may be floating debris in the bladder. Leukoplakia of the bladder may undergo cancerous changes, so biopsy and long term follow up are usually indicated. Anal canal
Leukoplakia of the anal canal is rare. It may extend up to the anorectal junction. On digital examination it feels hard and granular, and at proctoscopy, it appears as white plaques which may be diffuse, circumferential, or circumscribed. The histologic appearance is similar to oral leukoplakia, with hyperkeratosis and acanthosis. It may be asymptomatic, with symptoms due to other lesions such as hemorrhoids or fissures. Progression to anal stenosis has been described. The malignant potential is seemingly low, and few cases of anal carcinoma have been reported associated with anal leukoplaka. Signs and symptoms
Most cases of leukoplakia cause no symptoms, but infrequently there may be discomfort or pain. The exact appearance of the lesion is variable. Leukoplakia may be white, whitish yellow or grey. The size can range from a small area to much larger lesions. The most common sites affected are the buccal mucosa, the labial mucosa and the alveolar mucosa, although any mucosal surface in the mouth may be involved.