Variants of Gleason Pattern 4 (part 1)

 

Cribriform glands

Sheets of epithelium with multiple lumina. All invasive cribriform cancers without necrosis are now included in GP4 regardless of the size and shape of the glands. It may be difficult to distinguish between invasive cribriform carcinoma and intraductal carcinoma (IDC) on HE stains. Currently, grading of IDC is recommended but this is a controversial issue.

 

Cribriform gland with irregular borders. 

 

Cribriform gland (red arrow).

 

Cribriform gland that may be GP4, but difficult to exclude IDC on H&E.