Dysplasia is a word pathologists use to describe a group of cells showing an abnormal pattern of growth and maturation. Dysplasia can only be seen when the tissue is examined under the microscope. Dysplasia can happen anywhere in the body.
When dysplasia is found it is usually given a grade. Grade is a way of describing how different the abnormal cells are from the normal, healthy cells usually found in that location. In most parts of the body the grade will be divided into low to high. The cells in high grade dysplasia are more abnormal than the cells in low grade dysplasia.
In some parts of the body pathologists divide dysplasia into mild, moderate, and severe.
Why is this important? Tissue showing low grade (mild) dysplasia can return to normal over time or change to high grade dysplasia. High grade (severe) dysplasia is usually considered a pre-cancerous condition that can progress to cancer if left untreated.
The risk of tissue with dysplasia turning into a cancer depends on a number of factors including the type of tissue involved and the time from diagnosis to treatment.