J Korean Soc Radiol.  2019 Mar;80(2):351-358. 10.3348/jksr.2019.80.2.351.

IgG4-Related Hepatic Inflammatory Pseudotumor Complicated by Actinomycosis during Steroid Therapy

• Chung JW
• Bae YS
• Lim JH
• Lee DK
• Yu JS

• KMID: 2442526
• DOI: http://doi.org/10.3348/jksr.2019.80.2.351

Abstract

For a 67-year-old man with diabetes mellitus, a 9-cm liver mass was found on CT during the diagnostic work-up for weight loss and fever. Dynamic CT and MRI showed a layered pattern of contrast enhancement suggesting the imaging features of the solid inflammatory mass. After tissue diagnosis of immunoglobulin G4 (IgG4)-related disease by gun needle biopsy, steroid therapy induced partial shrinkage of the mass on the follow-up CT at 4 weeks. On the 5-month follow-up CT with the maintenance of low-dose oral steroid medication, disease progression with invasion to diaphragm brought surgical intervention of right hemihepatectomy considering the possibility of combined malignancy. In the area of diaphragmatic destruction, focal actinomycosis was complicated in the main mass of IgG4-related disease. We are the first to describe a rare case of IgG4-related inflammatory pseudotumor, complicated by actinomycosis, showing an invasive nature that mimicked malignancy during steroid therapy in a diabetic patient.

MeSH Terms

Actinomycosis*
Aged
Biopsy, Needle
Diabetes Mellitus
Diagnosis
Diaphragm
Disease Progression
Fever
Follow-Up Studies
Granuloma, Plasma Cell*
Humans
Immunoglobulins
Liver
Magnetic Resonance Imaging
Prednisolone
Weight Loss
Immunoglobulins
Prednisolone

Figure

• 

  Fig. 1 IgG4-related hepatic inflammatory pseudotumor complicated by actinomycosis during steroid therapy in a 67-year-old man presenting with fever and abdominal pain. A. Initial axial CT of arterial phase shows a large soft tissue mass consisted of internally inhomogeneous contrast enhancement surrounded by hypovascular rind (arrowheads) and adjacent parenchymal hyperemia in the right hepatic lobe (upper left). On the equilibrium phase of the same section of (upper left), contrast enhancement of the outer portion (arrowheads) looks stronger than the internal component and reflects fibrotic component in the peripheral portion of the lesion suggesting an inflammatory mass (upper middle). Axial T1-weighted (upper right) and T2-weighted (lower left) MRIs show roughly targetoid component of the same lesion, and apparent diffusion coefficient map (lower middle) shows peripheral area of high fluid contents (arrowheads) corresponding to the T1-weighted hypointensity and T2-weighted hyperintensity suggesting inflammation rather than solid tumor. Axial positron emission tomography-CT shows nonspecifically strong fludeoxyglucose uptake (lower right). B. Four-week follow-up axial CT in portal venous phase since the start of steroid therapy shows shrinkage of the lesion (arrowheads) in about 50% in volume (upper left). Two axial images of 5-month follow-up CT in portal venous phase since the start of steroid therapy shows the enlargement of the mass (arrowheads) with superiorly extended to the lower lobe of right lung across the right hemidiaphragm (upper right, lower left). Five-month follow-up coronal T2-weighted MRI (lower right) shows the mass (arrowheads) extended across the right hemidiaphragm (arrows), and preexisting hepatic cyst (asterisk). C. Gross photography and microscopic photographies of liver parenchyma and lung parenchyma after right hepatectomy and wedge resection from right lower lobe. Gross photography of the coronal section after mass excision (upper left) shows yellowish vaguely defined lesion, measuring 10 × 5 cm involving liver and lung parenchyma through the right hemidiaphragm. On the microscopy, lots of IgG4-positive plasma cells are scattered in the background of inflammatory cells (upper right; IgG4 staining, × 400). Focal actinomycotic colonies are also defined around the destructed right hemidiaphragm in the upper portion of the liver (lower left; H&E, × 40) and lower lung parenchyma (lower right; H&E, × 12.5). H&E = hematoxylin and eosin stain, IgG4 = immunoglobulin G4

Reference

1. Hedgire SS, McDermott S, Borczuk D, Elmi A, Saini S, Harisinghani MG. The spectrum of IgG4-related disease in the abdomen and pelvis. AJR Am J Roentgenol. 2013; 201:14–22.

2. Deshpande V, Zen Y, Chan JK, Yi EE, Sato Y, Yoshino T, et al. Consensus statement on the pathology of IgG4-related disease. Mod Pathol. 2012; 25:1181–1192.

3. Umehara H, Okazaki K, Masaki Y, Kawano M, Yamamoto M, Saeki T, et al. A novel clinical entity, IgG4-related disease (IgG4RD): general concept and details. Mod Rheumatol. 2012; 22:1–14.

4. Shibata M, Matsubayashi H, Aramaki T, Uesaka K, Tsutsumi N, Sasaki K, et al. A case of IgG4-related hepatic inflammatory pseudotumor replaced by an abscess after steroid treatment. BMC Gastroenterol. 2016; 16:89.

5. Kim YK, Kim CS, Lee JM, Ko SW, Moon WS, Yu HC. Solid organizing hepatic abscesses mimic hepatic tumor: multiphasic computed tomography and magnetic resonance imaging findings with histopathologic correlation. J Comput Assist Tomogr. 2006; 30:189–196.

6. Ahn KS, Kang KJ, Kim YH, Lim TJ, Jung HR, Kang YN, et al. Inflammatory pseudotumors mimicking intrahepatic cholangiocarcinoma of the liver; IgG4-positivity and its clinical significance. J Hepatobiliary Pancreat Sci. 2012; 19:405–412.

7. Yu JS, Park C, Kim JH, Chung JJ, Kim KW. Inflammatory myofibroblastic tumors in the liver: MRI of two immunohistochemically-verified cases. J Magn Reson Imaging. 2007; 26:418–421.

8. Lamba R, Fananapazir G, Corwin MT, Khatri VP. Diagnostic imaging of hepatic lesions in adults. Surg Oncol Clin N Am. 2014; 23:789–820.

9. Shah V, Arora A, Tyagi P, Sharma P, Bansal N, Singla V, et al. Intrahepatic cholangiocarcinoma masquerading as liver abscess. J Clin Exp Hepatol. 2015; 5:89–92.

10. Wong JJ, Kinney TB, Miller FJ, Rivera-Sanfeliz G. Hepatic actinomycotic abscesses: diagnosis and management. AJR Am J Roentgenol. 2006; 186:174–176.