Autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC) are the two most common immune-mediated chronic liver diseases encountered in clinical practice. Both conditions have well-established diagnostic criteria based on typical histological, serological, and clinical features [1,2]. However, the diagnosis of AIH-PBC overlap syndrome (OS) remains challenging due to the lack of widely accepted definitions and diagnostic criteria [3,4]. Currently, the “Paris criteria” is the most commonly used criteria for the diagnosis of OS, which requires the presence of at least two out of three key features for both PBC and AIH diagnoses [5].

Histological features play an essential role in the diagnosis of AIH, PBC, and OS. Although many cases of AIH and PBC display typical histologic features, some cases may not exhibit these features or display nonspecific histologic characteristics [1,6]. There is a need for a comprehensive morphological study that evaluates histologic features and correlates clinical findings for AIH, PBC, and OS. Our study aims to address this knowledge gap and improve the management and prognosis of patients with AIH, PBC, and OS.