85-year-old man with altered mental status   

History and images

Our appreciation is extended to Dr. Abdul Abid, University of Texas Medical Branch, for contributing this case.

History: An 85-year-old man with a previous history of percutaneous cholecystostomy tube placement following an episode of gangrenous cholecystitis presented with a fever and altered mental status. An abdominal computed tomography (CT) scan with contrast showed multiple hypoattenuating lesions within the liver, raising concern for malignancy. A liver biopsy was obtained. Photomicrographs are shown.

Click the images to enlarge.


What is the most likely diagnosis?
Immunoglobulin G4 (IgG4) disease
Hepatocellular carcinoma
Metastatic carcinoma
Inflammatory pseudotumor

Which immunohistochemical stain panel would help with the diagnosis?
IgG4 positive, anaplastic lymphoma kinase (ALK)‐1 negative, cluster of differentiation 1a (CD1a) negative
IgG4 negative, ALK-1 negative, CD1a negative
IgG4 negative, ALK-1 positive, CD1a negative
IgG4 negative, ALK-1 negative, CD1a positive