Inflammatory pseudotumors mimicking intrahepatic cholangiocarcinoma of the liver; IgG4-positivity and its clinical significance
ABSTRACT Inflammatory pseudotumor (IPT) of the liver is a benign condition with a good prognosis. However, it is difficult to distinguish clinical and radiological findings of IPT from those of malignancies. The aims of this study are to determine the clinical, radiological, and pathological characteristics, particularly relating to the role of the autoimmune mechanism in the development of inflammatory pseudotumours (IPTs) of the liver, and to suggest appropriate diagnostic and therapeutic strategy.
The clinical, diagnostic, and pathological characteristics including IgG4 immunohistochemical stain and follow-up data of 22 IPT patients were retrospectively analyzed.
The patients were 16 men and 6 women with a mean age of 59 years. Fifteen patients (68.2%) had associated biliary diseases. Of the 16 patients treated conservatively, the masses completely resolved in 10 patients, and reduced in size in 5 patients within the first 6 months. The remaining 6 patients were treated by surgical resection. IgG4 staining of 17 tissue samples from 22 patients were negative, most of the infiltrate being of fibrohistiocytic type, whereas 4 of 5 lymphoplasmacytic cells of dominant tumors show positive staining of IgG4. Although IgG4-related sclerosing cholangitis was mostly of lymphoplasmacytic type, other histological and clinical characteristics were similar in both types of IPTs.
IPTs of the liver can be diagnosed based on radiological and pathological findings by needle biopsy. Although the lymphoplasmacytic type of IPTs seems to correspond to IgG4-related disease, as assessed by IgG4 immunohistochemical stain, its clinical significance is unknown. Although most IPTs can be resolved with conservative therapy, surgical resection should be considered in cases of uncertain biopsy result, presumed malignant lesion, combination with other pathology, or lack of response to conservative management.
- Gastroenterology 05/2013; DOI:10.1053/j.gastro.2013.03.028 · 13.93 Impact Factor
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ABSTRACT: Immunoglobulin G4 (IgG4)-related disease is a novel disease entity that can involve diverse organs, causing specific diseases, including autoimmune pancreatitis, sclerosing cholangitis, cholecystitis, inflammatory aortic aneurysm, and inflammatory pseudotumor. IgG4-related disease is characterized by elevated serum IgG4 concentrations, abundant IgG4 lymphoplasmacytic infiltration, and dramatic steroid responses. It is clinically important to differentiate this rare disease from primary sclerosing cholangitis and cholangiocarcinoma, because the treatment and prognosis of these two diseases are completely different. However, the preoperative diagnosis is challenging, and the disease is frequently misdiagnosed. If the serum level of IgG4 is within the normal range, the diagnosis of IgG4-related disease is more difficult. This article reports on a 59-year-old man with IgG4-related disease mimicking unresectable gallbladder cancer with normal serum IgG4 concentrations.Gut and liver 09/2013; 7(5):616-20. DOI:10.5009/gnl.2013.7.5.616 · 1.49 Impact Factor
- Liver international: official journal of the International Association for the Study of the Liver 09/2013; 34(6). DOI:10.1111/liv.12319 · 4.41 Impact Factor