Gleason Grading System - Patterns 1 Through 5

Patterns 1 Through 5

Gleason patterns are associated with the following features:

• Pattern 1 - The cancerous prostate closely resembles normal prostate tissue. The glands are small, well-formed, and closely packed.
• Pattern 2 - The tissue still has well-formed glands, but they are larger and have more tissue between them.
• Pattern 3 - The tissue still has recognizable glands, but the cells are darker. At high magnification, some of these cells have left the glands and are beginning to invade the surrounding tissue.
• Pattern 4 - The tissue has few recognizable glands. Many cells are invading the surrounding tissue
• Pattern 5 - The tissue does not have recognizable glands. There are often just sheets of cells throughout the surrounding tissue.

In the United Kingdom, prostate cancer of Gleason pattern 1 and 2 are almost never seen. Gleason pattern 3 is by far the most common.