Gleason score 8 to 10
Monday 19 March 2012
The 2005 International Society of Urological Pathology (ISUP)-modified Gleason grading scheme defines several gland arrangements of high Gleason grade patterns 4 and 5.
Three patterns not defined in the 2005 ISUP scheme have been characterized, including single file, nested, and solid cylinder arrangements.
As aggressive and potentially lethal prostate cancer is most often of Gleason score 8 to 10, it is important for diagnostic recognition purposes to be aware of the frequency of various patterns encountered in high Gleason score 8 to 10 adenocarcinomas, the types of pattern admixtures, and the histomorphologic presentation of unusual patterns.
For some authors, Gleason grade assignments should incorporate single file, solid nested, and solid cylinder arrangements as high-grade pattern 5 because of the absence of glandular luminal space formation. (22367295)
Gleason pattern 4
In Gleason pattern 4, the glands appear fused, cribriform or they may be poorly defined. Fused glands are composed of a group of glands that are no longer completely separated by stroma. The edge of a group of fused glands is scalloped and there are occasional thin strands of connective tissue within this group. Cribriform pattern 4 glands are large or they may be irregular with jagged edges. As opposed to fused glands, there are no strands of stroma within a cribriform gland. Most cribriform invasive cancers should be assigned a pattern 4 rather than pattern 3. Poorly defined glands do not have a lumen that is completely encircled by epithelium. The hypernephromatoid pattern described by Gleason is a rare variant of fused glands with clear or very pale staining cytoplasm.
Gleason pattern 5
In Gleason pattern 5, there is an almost complete loss of glandular lumina. Only occasional lumina may be seen. The epithelium forms solid sheets, solid strands or single cells invading the stroma. Care must be applied when assigning a Gleason pattern 4 or 5 to limited cancer on needle biopsy to exclude an artefact of tangential sectioning of lower grade cancer. Comedonecrosis may be present.
Usual and Unusual Histologic Patterns of High Gleason Score 8 to 10 Adenocarcinoma of the Prostate in Needle Biopsy Tissue. Gottipati S, Warncke J, Vollmer R, Humphrey PA. Am J Surg Pathol. 2012 Feb 24. PMID: 22367295