Table 1.

Features used in histological assessment. Definitions and percent response of all pathologists for each item in cases of Biliary Atresia (BA) and non-BA

ITEM	DEFINITION	% RESPONSES
		BA CASES	NON-BA CASES
Visible bile plugs	absent	9	30
	canalicular only	22	47
	bile duct only	6	1
	bile duct and canalicular	63	22
Hepatocellular swelling1	absent/rare	30	23
	<50% of hepatocytes	47	32
	>50% of hepatocytes	23	45
Steatosis2	absent/rare	80	88
	<50% of hepatocytes	19	10
	>50% of hepatocytes	1	2
Pseudorosette formation	absent/rare	47	55
	present	45	37
	prominent	8	7
Hepatocellular multinucleation3	absent/rare	49	41
	present	37	36
	prominent	14	23
Hepatocellular necrosis	absent/rare	65	63
	few hepatocytes	31	32
	many hepatocytes	4	5
Extramedullary hematopoiesis	absent/rare	48	40
	present	47	36
	extensive	5	23
Lobular fibrosis4	absent	80	68
	present	17	23
	prominent	3	8
Portal tract edema	absent	55	90
	present	45	10
Grading of portal fibrosis	absent or fibrous expansion of some portal areas	8	60
	fibrous expansion of most portal areas	22	26
	focal portal-to-portal bridging	34	11
	marked bridging	24	3
	cirrhosis	12	0
Portal cellular infiltrate5	absent/minimal	13	40
	mild	59	40
	moderate/marked	28	20
Acute cholangitis6	absent	63	86
	present in occasional ducts	34	13.5
	marked	3	0.5
Periductular neutrophils	absent	31	57
	mild –present around occasional ducts	57	38
	marked	12	5
Mononuclear inflammatory cells in ducts7	absent	69	81.5
	mild- present in occasional ducts	30	18
	multiple	1	0.5
Ductal plate malformation	absent	86	99.5
	present	14	0.5
Bile ductular proliferation	none	4	54
	focal	19	24
	generalized	76	22

¹Hepatocellular swelling: Swelling is enlargement of the cell with rarefaction of the cytoplasm, in the absence of distinct vacuoles

²Steatosis: Refers to micro- and macro-vesicular steatosis

³Hepatocellular multinucleation (Giant cell transformation): Giant cell transformation means multinucleated (3 or more nuclei) hepatocytes independent of cell size. Cell swelling is scored separately.

⁴Lobular fibrosis: Evaluated using trichrome stain, assessing only zone 3

⁵Portal cellular infiltrate: Includes extramedullary hematopoiesis

⁶Acute cholangitis: Presence of neutrophils in duct or ductules, or infiltrating biliary epithelium. Ducts or ductules defined as a lumen with a cuboidal epithelium.

⁷Mononuclear inflammatory cells in ducts: Also if infiltrating biliary epithelium