Table 2.

Causes of Secondary Sclerosing Cholangitis and Mimics of PSC

Infectious Causes	AIDS cholangiopathy (eg, Cryptosporidium parvum, cytomegalovirus)
	Helminthic infection (eg, Clonorchis, Opisthorchis, Ascaris)
	Recurrent pyogenic cholangitis (also referred to as oriental cholangio-hepatitis)
Intrinsic or Extrinsic Compressive Causes (Benign or Malignant)	Mirizzi syndrome
	Cholangiocarcinoma
	Diffuse intrahepatic malignancy
	Compressive lymphadenopathy
	Portal hypertensive biliopathy
	Postoperative strictures
	Chronic pancreatitis
Immunologic Causes	IgG4-associated cholangiopathy
	Eosinophilic cholangitis
	Mast cell cholangiopathy
	Histiocytosis X
	Systemic vasculitis
	Hepatic allograft rejection
	Primary biliary cholangitis
Ischemic Causes	Posttransplant nonanastomotic strictures
	Postintraarterial chemotherapy
	Postradiation therapy
Congenital and/or Idiopathic Causes	Choledochal cyst (eg, Caroli disease)
	Progressive familial intrahepatic cholestasis

IgG4, immunoglobulin G subclass 4; PSC, primary sclerosing cholangitis.