INTRODUCTION
Immunoglobulin G subclass 4 (IgG4)-related disease (IgG4-RD) is a
relatively new and emerging immune-mediated disease with the prevalence
of approximately 0.28 to 1.08 per 100,000 population.1Initially linked with autoimmune pancreatitis (AIP) this immune-mediated
fibro-inflammatory condition, now virtually has been described in all
organ system: biliary tree, salivary glands, periorbital tissues,
kidneys, lungs, lymph nodes, meninges, aorta, breast, prostate, thyroid,
pericardium and skin.2, 3 On histopathology, affected
organ/tissue presents as tumor-like lesions with dense lymphoplasmacytic
infiltrates enriched with IgG4 positive plasma cells, characteristic
“storiform” fibrosis, obliterative phlebitis and increased
eosinophils.4 Serum IgG4 level is elevated but is not
a specific marker of the disease.5
IgG4-related sclerosing cholangitis (IgG4-SC) is the most common
extrapancreatic manifestation of IgG4-RD. It affects the biliary tree
which usually occurs along with autoimmune pancreatitis
(AIP).3, 6 Clinically, they present as obstructive
jaundice, and cholangiographic findings may suggest cholangiocarcinoma
or primary sclerosing cholangitis. Presence of the hypermetabolic bile
duct mass goes along with the cholangiocarcinoma. Clinical course,
treatment and prognosis vary between these two, thus needs proper
differentiation, though may be difficult.7 IgG4
responds to glucocorticoid therapy, whereas cholangiocarcinoma may need
surgery with or without chemotherapy.8
Herein, we report a case of a male who presented with features of
obstructive jaundice mimicking cholangiocarcinoma without the features
of acute pancreatitis, and responded well to the steroid therapy.