INTRODUCTION: IgG4-positive multiorgan lymphoproliferative syndrome (IgG4+ MOLPS) is a new clinical entity characterized by elevated serum IgG4, plasma cell infiltrates in tissues and good response to corticosteroid therapy. IgG4+ MOLPS includes autoimmune pancreatitis, sclerosing cholangitis, inflammatory pseudotumors of the lung, liver and breast and many other inflammatory conditions in multiple organs. We report the case of a patient with sclerosing cholangitis, presenting with inflammatory pseudotumors of the lung in which the diagnosis was made after twelve years from the initial symptoms.
CASE PRESENTATION: This 70 year-old man was referred to our institution in November 2009 for the elucidation of recurrent pulmonary infiltrates. In 1998 he was diagnosed with sclerosing cholangitis after a cholecystectomy for gallstones. Few sessions of dilatation of bile ducts by endoscopic retrograde cholangiopancreatography were done and a good symptomatic control was referred with ursodeoxicolic acid. There was no inflammatory bowel disease associated. In 2004 a lower lobe pulmonary nodule detected in a routine abdominal CT (with no signs of liver disease, but changes in size and echogenicity of the pancreas, suggesting chronic pancreatitis) was ressected and diagnosed as an inflammatory pseudotumor. Four years later he developed recurrent episodes of dyspnea and fatigue, with chest CT showing, along the years, different image patterns, predominantly bilateral peripheral nodules or subpleural consolidations with ground-glass halo. The symptoms and images responded to prednisone with recrudescence of the clinical picture following tapering of the corticosteroid. A search for autoimmune diseases was done several times, always with negative results. As commorbidities, the patient suffered from diabetes since 2000 and became insulin-dependent just after diagnosis. The association of an indolent cholangitis, a presumable autoimmune pancreatitis with endocrine insufficiency and inflammatory pseudotumors of the lung led us to the hypothesis of IgG4+MOLPS. The serum IgG4 concentration was 936 UI (reference values: <140 UI). A revision of the pulmonary nodule biopsy revealed a dense fibrosis with plasmacytic infiltration and focal lymphoid aggregation. Small number of eosinophils were seen (<5/high power field in most areas). Some vessels were partially or completely obstructed by inflammatory cells. Most of the infiltrating plasma cells were positive for IgG4, and IgG4/IgG ratio was over 90%. There was no light chain restriction (normal range of kappa: lambda) and no signs of malignancy.
DISCUSSIONS: A high serum IgG4 linked disease was first described in 2001, associated with sclerosing pancreatitis. This report was followed by others showing a similar involvement of multiple organs, such as pancreas, bile duct, gallbladder, salivary gland, retroperitoneum, kidney, lung, and prostate, denominated IgG4-related sclerosing disease. Recently, a new clinical entity, IgG4+MOLPS, has been proposed as an etiology for IgG4 plasma cell infiltrates in multiple organs and good response to glucocorticoids, as shown in this case.
CONCLUSION: When faced with inflammatory pseudotumors (histologically corresponding to plasma cell granuloma) or migratory pulmonary infiltrates with good response to corticosteroid therapy, the diagnosis of IgG4+MOLPS should be considered in the differential diagnosis. This may lead to a correct treatment and avoid unnecessary lung resections.
DISCLOSURE: Olivia Dias, No Financial Disclosure Information; No Product/Research Disclosure Information