Your pathology report for low grade squamous dysplasia of the esophagus

By Jason Wasserman MD PhD FRCPC
February 19, 2026

Low-grade squamous dysplasia of the esophagus is a precancerous condition in which the cells lining the esophagus show mild abnormal changes.

The esophagus is the muscular tube that carries food from the mouth to the stomach. Its inner surface is lined by squamous epithelium, a thin protective layer of flat cells. These cells normally grow, mature, and replace themselves in an orderly way.

In low-grade squamous dysplasia, the squamous cells begin to grow and look slightly abnormal under the microscope. The term “low grade” means that the changes are mild and limited in extent. Although this condition is not cancer, it is considered precancerous because the abnormal cells have the potential to progress to high-grade dysplasia or squamous cell carcinoma over time.

What symptoms can occur with low-grade squamous dysplasia?

Low-grade squamous dysplasia usually does not cause symptoms, especially in its early stages. Most people are diagnosed after an upper endoscopy performed for other reasons.

If symptoms are present, they are often related to the underlying condition that caused the dysplasia rather than the dysplasia itself. These symptoms may include difficulty swallowing, a burning sensation in the chest from acid reflux, or a feeling that food is sticking in the esophagus.

Because low-grade squamous dysplasia is often silent, it is commonly discovered during evaluation for chronic heartburn, swallowing problems, or other esophageal symptoms.

What causes low-grade squamous dysplasia?

Low-grade squamous dysplasia develops after repeated damage to the lining of the esophagus.

One of the most common causes is chronic acid reflux, also called gastroesophageal reflux disease. Long-term exposure to stomach acid can irritate and injure the squamous cells, leading to abnormal growth.

Tobacco use is another important risk factor. Smoking exposes the esophageal lining to harmful chemicals that can damage DNA inside the cells. Heavy alcohol use can also injure the lining of the esophagus and increase the risk of abnormal cellular changes.

Other causes of chronic irritation, such as repeated exposure to very hot liquids or ongoing inflammation, may also contribute. Reducing or eliminating these risk factors can help decrease the likelihood that dysplasia will worsen.

How is this diagnosis made?

The diagnostic process usually begins with an upper endoscopy, during which a doctor examines the esophagus using a thin, flexible tube with a camera. If an abnormal area is seen, a small tissue sample called a biopsy is taken.

The diagnosis of low-grade squamous dysplasia is made after a pathologist examines the biopsy under a microscope. The pathologist evaluates the cells to determine whether abnormal changes are present and whether those changes meet the criteria for low-grade dysplasia.

Microscopic features

The esophagus is lined by squamous epithelium, which is organized in layers. In healthy tissue, the cells near the bottom of the epithelium divide and gradually mature as they move toward the surface.

In low-grade squamous dysplasia, the squamous cells show mild abnormalities. The cells may have enlarged nuclei, which are the parts of the cell that contain genetic material. The nuclei may appear slightly darker than normal and may vary somewhat in size and shape. The cells may also appear crowded or slightly disorganized.

These abnormal changes are usually limited to the lower portion of the epithelium, typically involving the lower half. The upper layers of the epithelium still show normal maturation, which helps distinguish low-grade dysplasia from high-grade dysplasia.

What does “low grade” mean?

The term low grade refers to the severity of the abnormal changes seen under the microscope. In low-grade dysplasia, the changes are mild and limited in extent. The cells still resemble normal squamous cells to some degree, and the overall epithelial structure is partially preserved.

Low-grade dysplasia carries a lower risk of progression to cancer compared with high-grade dysplasia. However, it is still considered a precancerous condition and requires monitoring.

What is the risk of developing esophageal cancer?

The overall risk of low-grade squamous dysplasia progressing to squamous cell carcinoma of the esophagus is generally low. However, a small number of cases may worsen over time and develop into high-grade dysplasia or invasive cancer.

The risk of progression depends on several factors, including continued exposure to risk factors such as smoking or heavy alcohol use, the presence of ongoing inflammation, and individual patient factors.

Because there is a small but real risk of progression, regular monitoring with repeat endoscopy and biopsy is often recommended. Careful follow-up allows doctors to detect any worsening changes early, when treatment is most effective.

Questions to ask your doctor

• How certain is the diagnosis of low-grade squamous dysplasia?

• What is my individual risk of progression to cancer?

• How often should I have follow-up endoscopies?

• Should I make lifestyle changes, such as quitting smoking or reducing alcohol use?

• Are there treatments available to reduce the risk of progression?