Oral epithelial dysplasia

by Jason Wasserman MD PhD FRCPC
July 17, 2024

Background:

Oral epithelial dysplasia (OED) is a precancerous condition characterized by abnormal changes in the epithelial cells lining the oral cavity. These changes indicate that the cells are growing and maturing abnormally, which can potentially progress to oral squamous cell carcinoma if not properly managed. Oral epithelial dysplasia can appear as white patches (leukoplakia), red patches (erythroplakia), or mixed red and white patches (erythroleukoplakia) in the mouth. These lesions are usually found on the tongue, the floor of the mouth, the inside of the cheeks, or the gums.

What are the symptoms of oral epithelial dysplasia?

Oral epithelial dysplasia often presents with subtle symptoms that can vary in appearance and severity. Recognizing these symptoms early is crucial for timely diagnosis and management. The symptoms can include:

• White patches (leukoplakia): One of the most common signs is the appearance of white patches on the mucous membranes of the mouth. These patches may have a smooth or rough texture and cannot be easily scraped off.
• Red patches (erythroplakia): Less common but more concerning than leukoplakia, red patches may develop. These areas are usually velvety in texture and can indicate a higher risk of progression to cancer.
• Mixed red and white patches (erythroleukoplakia): Sometimes, both red and white areas are present within the same lesion. These mixed patches can signify a higher degree of dysplasia.
• Thickened or rough areas: The affected regions of the oral mucosa may become thickened or rough to the touch, indicating hyperplastic (increased growth) changes.
• Persistent sores or ulcers: Sores or ulcers that do not heal within a couple of weeks may be a symptom of dysplasia. These lesions can be painful or painless.
• Pain: Although oral epithelial dysplasia is often painless, some individuals may experience discomfort or pain, particularly when the lesion is irritated by eating, drinking, or dental appliances.
• Difficulty eating or swallowing: In more advanced cases, dysplastic lesions can interfere with normal oral functions, causing difficulty with eating or swallowing.

What causes oral epithelial dysplasia?

The most common cause of oral epithelial dysplasia is smoking. Other causes include excessive alcohol consumption, immune suppression, and inflammatory conditions such as lichen planus.

How is the diagnosis of oral epithelial dysplasia made?

The diagnosis of oral epithelial dysplasia is usually made after a small tissue sample is removed in a procedure called a biopsy. The biopsy is usually performed because you or your doctor saw an abnormal-looking area of tissue within your oral cavity. Your pathology report will probably say what part of the oral cavity was sampled in the biopsy. The diagnosis can also be made after a larger piece of tissue is removed in a procedure called an excision.

How is oral epithelial dysplasia graded?

Oral epithelial dysplasia is graded based on the severity of the cellular abnormalities observed under the microscope. There are two grading systems currently used by pathologists:

Three-tier grading system

This system divides oral epithelial dysplasia into three categories based on the extent of abnormal changes:

Mild dysplasia

In mild oral epithelial dysplasia, the abnormal changes are limited to the lower third of the epithelial layer. Microscopically, there are slight abnormalities in cell shape and arrangement, along with mild nuclear changes. The risk of cancer progression is relatively low, requiring monitoring and potential removal of the lesion if it persists.

Moderate dysplasia

Moderate oral epithelial dysplasia involves abnormal changes extending into the middle third of the epithelial layer. These changes are more pronounced than in mild dysplasia, with greater abnormalities in cell shape, arrangement, and nuclear features. Compared to mild dysplasia, there is a higher risk of progression to cancer, which may necessitate more aggressive treatment, including surgical excision and closer follow-up.

Severe dysplasia

Severe oral epithelial dysplasia is characterized by abnormal changes involving more than two-thirds of the epithelial layer but not extending through its full thickness. This stage shows marked abnormalities in cell shape, arrangement, and nuclear changes, with the presence of mitotic figures (cells undergoing division) higher up in the epithelial layer. The risk of progression to squamous cell carcinoma is significant, usually necessitating surgical excision and thorough monitoring.

Two-tier grading system

This system simplifies the classification into two categories based on the overall risk of progression to cancer:

Low grade dysplasia

Low grade oral epithelial dysplasia includes changes that would be classified as mild dysplasia and some cases of moderate dysplasia in the three-tier system. Microscopically, there are mild to moderate abnormalities in cell shape and arrangement, with fewer mitotic figures. The risk of cancer progression is lower, and management typically involves regular monitoring and conservative treatment.

High grade dysplasia

High grade oral epithelial dysplasia encompasses changes that would be classified as severe dysplasia and carcinoma in situ, as well as some cases of moderate dysplasia in the three-tier system. This category is characterized by severe cellular and nuclear abnormalities, numerous mitotic figures, and potential involvement of the full thickness of the epithelium. The risk of progression to squamous cell carcinoma is high, often requiring surgical removal and close follow-up to prevent invasive cancer.

About this article

This article was written by doctors to help you read and understand your pathology report. Contact us with any questions about this article or your pathology report. Read this article for a more general introduction to the parts of a typical pathology report.

Other helpful resources

Atlas of Pathology