Immunoglobulin G4-related disease (IgG4-RD) is a recently characterized illness in which lymphocytes and plasma cells infiltrate various anatomical sites. IgG4-hepatopathy, a manifestation of
IgG4-RD, is a broader term covering various patterns of liver injury. The
clinical course, including the malignant potential of
IgG4-RD, remains unclear. Here we report the first case of secondary
hemochromatosis and
hepatocellular carcinoma (HCC) developing from IgG4-hepatopathy. A 67-year-old man was admitted to our hospital for treatment of deteriorating
glucose tolerance. Blood test results showed
hypergammaglobulinemia, especially
IgG4. He was readmitted 2 months later with
dyspnea due to
lung disease and
pleural effusion, and elevated
transaminase levels. He underwent liver and lung biopsies.
IgG4-RD was diagnosed and he was treated with
steroid therapy, which improved serum
IgG4 levels and imaging abnormalities. A follow-up computed tomography (CT) scan conducted 38 months later revealed a
tumor (diameter, 50 mm) in liver segments 7 and 8. The resected specimen revealed HCC and abundant
siderosis in the background liver, indicating a diagnosis of
hemochromatosis. IgG4-positive cells were scarce, probably because of
corticosteroid therapy. In the present case,
IgG4-RD was well controlled with
prednisolone (PSL) and an
immunosuppressive agent, and
chronic hepatitis was not severe, even though the patient subsequently developed HCC. However, extensive
siderosis consistent with
hemochromatosis was unexpectedly noted. These findings suggest that secondary
hemochromatosis and HCC developed during
IgG4-RD with hepatopathy. We believe this case sheds light on
IgG4-RD.