By Jason Wasserman MD PhD FRCPC
May 22, 2025
Squamous intraepithelial neoplasia of the esophagus is a precancerous condition that involves abnormal changes in the cells lining the esophagus. The esophagus is the muscular tube that carries food from your mouth to your stomach. “Squamous” refers to the type of cells affected, which are flat cells normally lining the inner surface of the esophagus. “Intraepithelial” means that the abnormal cells are limited to the surface layer and have not spread deeper into surrounding tissues. “Neoplasia” means new, abnormal cell growth, which in this case, can potentially develop into cancer.
Is squamous intraepithelial neoplasia a cancer?
No, squamous intraepithelial neoplasia is not a cancer. It is a precancerous condition, meaning the abnormal cells are limited to the surface layer of the esophagus and have not invaded deeper tissues or spread to other parts of the body. However, if left untreated, especially when high-grade changes are present, it can potentially progress into a type of esophageal cancer called squamous cell carcinoma.
What causes squamous intraepithelial neoplasia?
Squamous intraepithelial neoplasia is most commonly caused by factors that damage the lining of the esophagus over time. These factors include smoking, heavy alcohol use, poor nutrition, and chronic irritation from conditions such as gastroesophageal reflux disease (GERD). Long-term exposure to these factors can lead to cell damage and abnormal growth.
What are the symptoms of squamous intraepithelial neoplasia?
Most people with squamous intraepithelial neoplasia do not experience any symptoms. It is usually discovered incidentally during tests performed for other reasons. Occasionally, some people might experience vague symptoms such as mild discomfort or difficulty swallowing, but these symptoms are typically related to other underlying conditions rather than the neoplasia itself.
How is this diagnosis made?
The diagnosis of squamous intraepithelial neoplasia is made by examining a tissue sample under the microscope. This tissue sample is obtained during an endoscopy, where a doctor inserts a thin, flexible tube with a camera into your esophagus to visually inspect the lining and take small biopsies from any abnormal-looking areas.
A pathologist then examines these tissue samples under a microscope to determine whether abnormal cells are present and to assess their severity.
Low versus high grade squamous intraepithelial neoplasia
Squamous intraepithelial neoplasia is classified into two grades based on the degree of abnormality:
- Low grade squamous intraepithelial neoplasia means the abnormal changes are mild. In many cases, low-grade changes may improve or resolve completely, especially if the underlying cause (such as smoking or acid reflux) is addressed.
- High grade squamous intraepithelial neoplasia means the abnormal cells show more significant changes. If left untreated, these changes carry a higher risk of developing into squamous cell carcinoma, a type of esophageal cancer.
What is the risk of developing cancer with squamous intraepithelial neoplasia?
The risk of developing cancer depends on the grade of the neoplasia:
- For low grade squamous intraepithelial neoplasia, the risk of progressing to cancer is very low, particularly if the underlying causes are managed appropriately.
- For high grade squamous intraepithelial neoplasia, the risk is significantly higher, and closer monitoring or treatment is generally recommended to prevent progression to cancer.
Questions to ask your doctor
- What grade of squamous intraepithelial neoplasia do I have?
- Do I need treatment, or is monitoring sufficient?
- How often should I have follow-up endoscopies?
- Are there lifestyle changes I should make to reduce my risk?
- What are the signs that my condition might be getting worse?
- Should I be screened for other related conditions or cancers?
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