Histopathological assessment of granulomatous hepatitis: a retrospective study

Liver granulomas (LG) are reported in 1-15% of liver biopsies and determining the aetiology can be challenging due to a wide range of aetiologies. The aim of this study was to describe the clinicopathological findings of LG. A retrospective review was performed of histopathological reports at South African tertiary academic centres from January 2014 to December 2022 to determine the demographics, micro-anatomical distribution, histopathological subtypes and the aetiology of LG. There were 2166 liver biopsy specimens submitted for histopathology during the study timeframe. LG were documented in 209 cases (9.6%) and non-necrotizing granulomas predominated (68.9%). The granulomas were mostly distributed in the parenchymal lobular region (44,1%), 32.5% were noted within parenchymal and portal regions, while 23.4% were noted in the portal tracts. Infections comprised 38.8% with mycobacterial infection predominating (30.2%), idiopathic granulomatous hepatitis (IGH) accounted for 35.5% and 25.8% had a non-infectious aetiology inclusive of drug induced liver injury (10.5%), sarcoidosis (7.7%), autoimmune disease (5.7%) and neoplasia (1.8%). LG were evident in 108 HIV-seropositive patients (47.4%) and granulomas due to mycobacterial infection were more frequent in HIV-positive individuals when the CD4 count was <200 cells/μL. IGH occurred predominantly in females aged 40-59 years and displayed non-necrotizing granulomas (70.3%) with parenchymal distribution (51.4%). HIV and TB co-infection was frequent and significantly associated with low CD4 counts. The findings hereof reinforce the link between TB-related LG and immunocompromised status. IGH cases were present in middle-aged females with non-necrotizing granulomas detected predominantly in the parenchymal lobules.