Morphological aspects of small-duct cholangiopathies: A minireview

Table 1 Morphological classification of cholangiopathies

Pattern of biliary injury		Disease
Cholangitis	Neutrophilic	Infection, sterile
	Lymphocytic	PBC, GVHD, allograft rejection
	Pleomorphic	AIH, PBC, DILI
	Granulomatous	PBC, sarcoidosis, DILI
	Sclerosing	PSC, IgG4-sclerosing cholangitis, DILI
Bile duct loss and ductopenia		See Table 2
Ductal plate malformation		See Table 3
Neoplastic		BilIN, IPN, cholangiocarcinoma

PBC: Primary biliary cholangitis; GVHD: Graft-versus-host disease; AIH: Autoimmune hepatitis; DILI: Drug induced liver injury; PSC: Primary sclerosing cholangitis; BilIN: Biliary intraepithelial neoplasia; IPN: Intraductal papillary neoplasia.

Table 2 Conditions associated with ductopenia

Infantile and childhood diseases	Bile duct paucity (syndromic/non-syndromic)
	Extrahepatic biliary atresia
	Progressive familial intrahepatic cholestasis
	Fibropolycystic disease
	Alpha-1 antitrypsin deficiency
Immune-mediated diseases	Primary biliary cholangitis
	Primary sclerosing cholangitis
	Chronic graft-versus-host disease
	Chronic hepatic allograft rejection
	Hepatic sarcoidosis
Vascular diseases	Ischaemic cholangiopathy
	Portal biliopathy
Infectious diseases	Ascending cholangitis
	Protozoal and parasitic infestations
Drug- or toxin-induced biliary injury
Neoplastic diseases	Hodgkin’s lymphoma
	Langerhans cell histiocytosis
	Systemic mastocytosis
Idiopathic	Idiopathic adulthood ductopenia

Table 3 Ductal plate malformation – genes and encoded proteins

Disorder	Gene	Product
ARPKD	PKHD	Fibrocystin/polyductin
ADPKD	PKD1	Polycystin 1
	PKD2	Polycystin 2
	GANAB/PKD3	Glucosidase II alpha subunit
PCLD	PRKCSH	Glucosidase II beta subunit
	ALG8	Alpha-1,3-glucosyltransferase
	SEC61B	SEC61 translocon subunit beta
	SEC63	Translocon component in the endoplasmic reticulum
	LRP5	LDL receptor-related protein 5
CHF-SC	ZFYVE19	Zinc finger FYVE-type containing 19

ARPKD: Autosomal recessive polycystic kidney disease; ADPKD: Autosomal dominant polycystic kidney disease; PCLD: Polycystic liver disease (without kidney); CHF-SC: Congenital hepatic fibrosis and sclerosing cholangiopathy.