Inflammatory Pseudotumor of the Liver

Area of Science:

• Pathology
• Hepatology
• Oncology

Background:

• Hepatic inflammatory pseudotumor (IPT) is a mass lesion characterized by fibroblasts/myofibroblasts and inflammatory cells.
• IPTs are thought to result from an exaggerated response to infectious agents, though the cause is often unidentified.

Purpose of the Study:

• To outline the diagnostic considerations for hepatic inflammatory pseudotumors.
• To emphasize the importance of excluding infectious and neoplastic mimics.

Main Methods:

• Review of the histopathological features of IPT.
• Discussion of ancillary diagnostic techniques.
• Differential diagnosis of hepatic mass lesions.

Main Results:

• IPTs require exclusion of specific infections (e.g., mycobacteria, Candida, syphilis).
• IgG4-related disease can present as a plasma-cell rich IPT.
• Neoplastic conditions such as inflammatory myofibroblastic tumor and lymphomas can mimic IPTs.

Conclusions:

• Accurate diagnosis of hepatic inflammatory pseudotumor relies on excluding infections and neoplasms.
• Ancillary studies are crucial for differentiating IPT from mimicking conditions.
• Pathologists must consider a broad differential diagnosis for hepatic inflammatory pseudotumor.