85-year-old man with altered mental status   

Findings and diagnosis

Microscopic findings

The core needle biopsies show that the hepatic architecture is largely replaced by fibrosis, fibroblasts, and mixed inflammation (neutrophils, eosinophils, plasma cells, lymphocytes, and macrophages). A few possible portal tract remnants are identified by reactive bile ducts without preserved hepatic arteries and portal veins. There is a prominent bile ductular reaction. Focally, abundant neutrophils are seen. Several areas contain reactive/atypical-appearing bile ducts; some even contain neutrophils within their epithelium and lumens.

Differential diagnosis

  • Hepatocellular carcinoma
  • Cholangiocarcinoma
  • IgG4 disease
  • Langerhans cell histiocytosis
  • Inflammatory pseudotumor

Diagnosis: Inflammatory pseudotumor