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Gleason pattern 4
Tuesday 31 July 2012
Gleason4
A controversial area where consensus was reached was that ill-defined glands with poorly formed glandular lumina also warrant the diagnosis of Gleason pattern 4.
Only a cluster of such glands, where a tangential section of Gleason pattern 3 glands cannot account for the histology, would be acceptable as Gleason pattern 4.
It was also noted that in most cases ill-defined glands with poorly formed glandular lumina are accompanied by fused glands.
Very small, well-formed glands still are within the spectrum of Gleason pattern 3. This definition differs from Gleason’s original description of pattern 4 which only included the hypernephromatoid pattern.
Only in subsequent years were fused glandular masses added to the definition.
The original schematic diagram of Gleason pattern 4 consisted almost entirely of cribriform patterns without depicting fused glands or ill-defined glands with poorly formed glandular lumina.
Gleason pattern 4 closely resembling renal cell carcinoma (hypernephromatoid pattern) makes up only a very small percentage of Gleason pattern 4 cases.
