Low grade squamous dysplasia of the esophagus

By Jason Wasserman MD PhD FRCPC
January 17, 2025


Low grade squamous dysplasia of the esophagus is a precancerous condition in which the cells lining the inside of the esophagus show abnormal growth. These cells are called squamous cells, and they normally form a thin, protective layer called the squamous epithelium. In low grade squamous dysplasia, the squamous cells begin to grow and look slightly abnormal under the microscope. The term “low grade” means the changes are mild, and the condition has a lower risk of turning into cancer compared to high grade squamous dysplasia.

squamous epithelium

What are the symptoms of low grade squamous dysplasia of the esophagus?

Low grade squamous dysplasia usually does not cause any symptoms, especially in the early stages. However, some people may experience symptoms related to the conditions that cause dysplasia, such as:

  • Difficulty swallowing (dysphagia).
  • Heartburn or acid reflux.
  • A sensation of food getting stuck in the esophagus.

If you have been diagnosed with low grade squamous dysplasia, it is often found during an upper endoscopy performed for other reasons, such as long-term heartburn or difficulty swallowing.

What causes low grade squamous dysplasia of the esophagus?

Low grade squamous dysplasia is caused by damage to the lining of the esophagus. Common causes include:

  • Chronic acid reflux (gastroesophageal reflux disease or GERD): Long-term exposure to stomach acid can irritate and damage the squamous cells lining the esophagus.
  • Smoking: Tobacco use is a major risk factor for squamous dysplasia in the esophagus.
  • Alcohol use: Heavy alcohol consumption can also damage the esophageal lining.
  • Chronic irritation or inflammation: This may occur from repeated exposure to hot liquids, spicy foods, or other irritants.

Addressing these causes can help reduce further damage and lower the risk of progression.

How is this diagnosis made?

The diagnosis of low grade squamous dysplasia is made by examining a small sample of tissue taken from the esophagus during a procedure called an upper endoscopy. The sample is processed and examined under a microscope by a pathologist, who looks for specific changes in the cells lining the esophagus.

What are the microscopic features of low grade squamous dysplasia of the esophagus?

The esophagus is lined by squamous epithelium, a thin layer of flat, protective cells called squamous cells. In low grade squamous dysplasia, these cells show abnormal changes.

Pathologists look for two types of changes when examining the tissue:

  1. Cytological atypia: These are changes in the squamous cells themselves, such as:
    • Enlarged nuclei (the part of the cell that contains DNA).
    • Irregular or uneven nuclear shapes.
    • Darker-than-normal staining of the nuclei.
    • Loss of normal cell organization, where the squamous cells no longer align neatly.
    • Overlapping of cells, where they crowd on top of each other.
  2. Architectural atypia: These are changes in how the squamous cells are arranged, including abnormal maturation of the epithelium.

In low grade squamous dysplasia, these changes are mild and usually affect only the lower half of the squamous epithelium.

What is the risk of developing esophageal cancer with low grade squamous dysplasia?

The risk of low grade squamous dysplasia progressing to esophageal cancer is generally low. However, some cases may worsen over time and develop into high grade dysplasia or cancer. The exact risk depends on factors such as your overall health, the presence of risk factors like smoking or alcohol use, and whether the underlying cause of the dysplasia is addressed.

Because there is a small risk of progression, regular monitoring with repeat endoscopies and biopsies is recommended. This helps ensure that any changes are detected and treated early, reducing the likelihood of developing cancer.

A+ A A-