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.
Liver Transplantation 05/2014; 20(5). DOI:10.1002/lt.23828 · 3.79 Impact Factor
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ABSTRACT: To assess gadoxetic acid-enhanced and diffusion-weighted (DW) magnetic resonance imaging (MRI) findings of inflammatory myofibroblastic tumours (IMTs) of the liver using combined 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET)/computed tomography (CT), and to evaluate clinical course with volume change on follow-up. Gadoxetic acid-enhanced and DW MRI findings of 18 histopathologically proven hepatic IMTs in 13 patients were retrospectively reviewed. The clinical features, qualitative (signal intensity and enhancement pattern) and quantitative data [apparent diffusion coefficient (ADC)], and analysis of FDG-PET/CT findings were collected. The volume of IMTs during follow-up was measured using a tumour half-time. Most of the IMTs (9/13, 69.2%) were found incidentally. IMTs were predominantly seen as well-defined (16/18, 88.9%) masses with peritumoural hypointensity during the hepatobiliary phase (17/18, 94.4%) and showed five morphological types: target-like hypervascular mass (n = 9), hypovascular mass (n = 5), heterogeneous enhancing mass (n = 2), sclerosing mass (n = 1), and non-target hypervascular mass (n = 1). All lesions showed diffusion restriction and hypermetabolic mass on FDG-PET/CT images. The mean ADC value and ADC ratio of IMTs to liver were 0.828 × 10(-3) mm(2)/s and 0.76, respectively. On follow-up, all 11 IMTs showed rapid regression (mean tumour half-time, 38.49 days) with no tumour recurrence or distant metastasis. Although hepatic IMTs can mimic abscess and malignant tumours at MRI and PET/CT, peritumoural hypointensity during the hepatobiliary phase with rapid regression on follow-up could be helpful for differentiating it from other lesions.Clinical Radiology 02/2014; DOI:10.1016/j.crad.2013.12.018 · 1.66 Impact Factor
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ABSTRACT: Inflammatory pseudotumor (IPT) of the liver is a rare disease characterized by chronic infiltration of inflammatory cells. However, the clinical characteristics and outcomes of IPT remain uncertain. Clinical features, image findings, and outcomes of 55 patients with histologically proven IPT were evaluated. They consisted of 26 men and 19 women with median age of 65 years. Serum carcinoembryonal antigen and carbohydrate antigen 19-9 levels were normal in 42 patients (93.3%). Enhanced CT scans indicated poorly defined peripheral enhancement (82.5%) at the arterial phase and poorly defined hyperattenuating lesions with internal hypoattenuating areas at the equilibrium phase (77.0%). Gadolinium-enhancement MRI revealed poorly defined peripheral rim-like enhancement (77.8%). Ten patients underwent surgical resection and 35 were treated conservatively with or without antibiotics. No recurrence was noted after surgical resection during follow-up (1 to 48 months). In all patients who received conservative treatment, complete resolution or size reduction was noted during follow-up (1 to 192 months). CT and MRI provide clues to the diagnosis of IPT in patients with liver masses and normal tumor markers. However, due to the lack of pathognomonic findings, the clinician's suspicion and histological diagnosis are necessary to make an accurate diagnosis of IPT.Gut and Liver 01/2014; 8(1):58-63. DOI:10.5009/gnl.2014.8.1.58 · 1.49 Impact Factor