Low-grade dysplasia in the colon refers to the presence of mildly abnormal cells within the lining of the large intestine. These cellular changes are not cancerous, but they indicate a deviation from normal cell growth and organization. This condition represents an early stage of atypical cell development that can be observed under a microscope.
What Exactly is Dysplasia?
Dysplasia describes abnormal cell growth or development within a tissue or organ. In the colon, this means the cells lining the intestinal wall exhibit changes in their appearance, arrangement, and growth patterns compared to healthy cells. A pathologist typically identifies these alterations by examining tissue samples.
Low-grade dysplasia signifies that the cells are only slightly abnormal. Their nuclei, which contain the cell’s genetic material, may be slightly enlarged or elongated, but they largely retain their normal characteristics and organization. This indicates a less severe degree of cellular change. Conversely, high-grade dysplasia involves cells that look much more abnormal and disorganized, bearing a closer resemblance to cancer cells.
Dysplasia, whether low-grade or high-grade, is not cancer. Dysplastic cells have not yet developed the ability to invade surrounding tissues or spread to other parts of the body, which are defining characteristics of cancer. However, dysplasia is considered a precancerous condition because, if left untreated, these abnormal cells have the potential to progress to cancer over time.
How Low-Grade Dysplasia is Discovered
Low-grade dysplasia in the colon is most commonly found during a colonoscopy, a procedure to examine the large intestine’s lining. During this procedure, any suspicious growths or abnormal tissue, such as polyps, can be identified. Polyps are small clumps of cells that form on the colon’s inner surface, and dysplasia often occurs within these growths.
If an abnormal area or polyp is observed, a small tissue sample, known as a biopsy, is taken during the colonoscopy. This sample is then sent to a pathology laboratory for examination. A pathologist, a medical doctor specializing in tissue analysis, examines the biopsy under a microscope.
The pathologist assesses the cells for features indicative of dysplasia, such as changes in cell shape, size, organization, and nuclear characteristics. Based on the degree of these changes, the pathologist determines the grade of dysplasia, classifying it as low-grade or high-grade.
Why Low-Grade Dysplasia Matters
While low-grade dysplasia is not cancer, it is considered a precancerous condition. These abnormal cells have the potential to develop into colorectal cancer if not monitored or removed. The risk of progression is generally lower compared to high-grade dysplasia.
Progression from low-grade dysplasia to more advanced stages, including high-grade dysplasia and eventually cancer, can occur over time. Identifying low-grade dysplasia allows for interventions that can prevent colorectal cancer development. Regular surveillance and appropriate management are important to interrupt this potential progression pathway and reduce future cancer risk.
Next Steps After a Low-Grade Dysplasia Diagnosis
Upon a diagnosis of low-grade dysplasia, the next step involves removing the dysplastic tissue. If found within a polyp, the entire polyp can often be removed during the colonoscopy, a procedure known as polypectomy. Complete removal of the abnormal tissue is important because these lesions are precancerous and can progress to colorectal cancer.
After removal, a surveillance plan is established, involving regular follow-up colonoscopies to monitor for new or recurring dysplasia. The timing of these colonoscopies varies based on factors like the number and size of polyps, their characteristics, and individual risk. For instance, patients with one or two small tubular adenomas with low-grade dysplasia might have their next colonoscopy in 5 to 10 years.
However, a higher number or larger polyps, or other elevated risk factors, might lead to a shorter follow-up interval, such as 3 years. A healthcare provider determines the specific management strategy based on the patient’s circumstances and medical history.