# Concomitant Autoimmune Liver Disease and Hepatic Actinomycosis: A Diagnostic Challenge—Brief Report and Review of the Literature

## TL;DR

This paper discusses a rare case where a liver condition was misdiagnosed multiple times before identifying an actinomycosis infection.

## Contribution

The novelty lies in highlighting the diagnostic challenges and the eventual role of multiple biopsies in identifying hepatic actinomycosis.

## Key findings

- Hepatic actinomycosis and IgG4-related pseudotumors are rare and often misdiagnosed.
- Molecular techniques like PCR can aid in diagnosing actinomycosis when conventional methods fail.
- Multiple liver biopsies were required to confirm the presence of actinomyces infection in this case.

## Abstract

Hepatic actinomycosis (HA) and IgG4-related inflammatory pseudotumors are rare and often overlooked causes of liver mass, which can easily be misdiagnosed as primary liver cancer or metastasis. Diagnosis is arduous due to unspecified clinical and radiological features and the fact that histology is not always conclusive. In cases of actinomycosis, the use of molecular diagnostic techniques—such as polymerase chain reaction (PCR) for bacterial DNA—can aid in establishing a definitive diagnosis, especially when conventional cultures are non-diagnostic. We present a case report of one of our patients who was incidentally diagnosed with a hepatic lesion presenting aspecific radiological features. Since radiological imaging was inconclusive, a biopsy was performed, and a diagnosis of IgG4 related hepatic inflammatory pseudotumor was then made. Because of the disease progression, during immunosuppressive therapy, our diagnosis was questioned and a new liver biopsy was carried out. At the end, it took three consequent biopsies to finally find out the presence of an actinomyces infection.