Table 4 Grading of CD34, smooth muscle actin and glutamine synthetase staining

CD34

 0 - no periportal sinusoidal staining or focal, (non-circumferential) periportal sinusoidal staining

 1 - circumferential periportal sinusoidal staining present

 2 - bridging (zone 1 to zone 1) sinusoidal staining present

 3 - 2 and midzonal to centrizonal (zone 2 to zone 3) staining

Smooth Muscle Actin

 0 - no apparent staining or rare isolated positive cells in the perisinusoidal space

 1 - many positive cells without linear/continuous pattern of perisinusoidal staining

 2 - focal linear/continuous pattern of perisinusoidal staining

 3 - multifocal linear/continuous perisinusoidal staining

Glutasmine Synthetase

 0 - normal perivenular staining pattern

 1 - focal midzonal (zone 2) staining present

 2 - multifocal midzonal (zone 2) staining present

 3 - unequivocal confluent midzonal to periportal staining, if any