Oral epithelial dysplasia is a condition involving abnormal cell changes in the lining of the mouth, known as the epithelium. These changes are considered precancerous, meaning they are not cancer but could progress into it over time. Dysplasia arises from damage to the cells’ DNA. A diagnosis of dysplasia serves as a warning that the affected tissue has an increased risk of developing into oral squamous cell carcinoma, the most common type of mouth cancer.
Identifying Oral Epithelial Dysplasia
Oral epithelial dysplasia is often discovered during a routine dental examination. It appears as a patch inside the mouth that can be white (leukoplakia), red (erythroplakia), or a mixture of red and white (erythroleukoplakia). It is estimated that 5% to 25% of lesions identified as leukoplakia will show dysplastic changes upon biopsy. These lesions can range in size from a few millimeters to several centimeters and may occasionally have an ulcerated surface. While dysplasia itself does not cause pain, the affected area might feel slightly sore.
These patches can appear anywhere in the oral cavity, but certain locations are more common, including the inside of the cheeks, the gums, and the tongue. Lesions found on the floor of the mouth, the sides of the tongue, and the soft palate carry a higher likelihood of showing dysplastic changes.
Causes and Risk Factors
Oral epithelial dysplasia is strongly linked to behaviors and risk factors that expose the mouth’s lining to carcinogens. A primary cause is tobacco use in all its forms, including smoking and smokeless products. Heavy consumption of alcohol is another significant contributor, and the risk is compounded when tobacco and alcohol are used together.
Other factors include chronic irritation from sources like ill-fitting dentures or the sharp edge of a broken tooth. There is also growing evidence linking dysplasia to the human papillomavirus (HPV). For lesions on the lips, prolonged sun exposure is a well-established cause (actinic cheilitis). In some populations, chewing betel quid or areca nut is also a major risk factor.
Diagnosis and Classification
A definitive diagnosis of oral epithelial dysplasia cannot be made by sight alone and requires a biopsy. This procedure involves a clinician taking a small tissue sample from the suspicious-looking area in the mouth. The collected sample is then sent to a laboratory where a pathologist views the tissue under a microscope. The pathologist examines the tissue’s overall structure and the individual cells for abnormalities.
Based on this microscopic analysis, dysplasia is classified into one of three grades: mild, moderate, or severe. In mild dysplasia, the atypical cells are confined to the lower third of the epithelium. Moderate dysplasia involves abnormalities extending into the middle third of the epithelial layer.
Severe dysplasia is characterized by atypical cells reaching into the upper third of the epithelium. This classification system is important because the grade of dysplasia helps predict the lesion’s likelihood of progressing to cancer and guides subsequent management decisions.
Management and Treatment Approaches
For cases diagnosed as mild dysplasia, the approach may be more conservative. This often involves a strategy of active surveillance, where the lesion is monitored through regular check-ups to see if it changes or resolves on its own. An important part of this approach is the elimination of any contributing risk factors, such as quitting smoking or reducing alcohol intake.
For moderate and severe dysplasia, treatment is recommended to remove the abnormal tissue and reduce the risk of cancer development. Surgical excision, which involves cutting out the entire lesion, is a common treatment method. Other removal techniques include laser ablation and cryosurgery. The choice of treatment depends on various factors, including the size and location of the lesion in addition to its grade. Even after successful removal, the area requires regular follow-up appointments.
Prognosis and Long-Term Outlook
The long-term outlook for an individual with oral epithelial dysplasia depends on the grade of the lesion and its management. The primary concern is the risk of malignant transformation, which is the likelihood that the dysplasia will progress to invasive squamous cell carcinoma. This risk is directly correlated with the grade, as mild dysplasia has a lower chance of transforming into cancer compared to severe dysplasia.
Even after a dysplastic lesion has been completely removed, long-term follow-up is necessary because the lesion may return. Regular check-ups with a dentist or specialist are required to monitor the site for any signs of recurrence and to inspect the entire oral cavity for new lesions. If any changes are noted during a follow-up visit, another biopsy may be necessary.