Granulomatous inflammation in histopathological samples: examining the aetiological spectrum, diagnostic challenges, and future perspectives.

What To Know

This study retrospectively reviewed 626 patients with granulomas identified on histopathology across multiple organs over 11 years. Gastrointestinal samples made up 25% of cases; overall the leading causes of granulomas were infectious diseases (especially mycobacteria), inflammatory bowel disease (IBD), sarcoidosis, and neoplasms.

The authors note differences by organ site and by patient origin (Western European patients more often had IBD; foreign patients had higher rates of tuberculosis). Microbiological cultures were performed in only about one-third of cases.

The paper argues for a more structured diagnostic algorithm to guide evaluation (histology, targeted microbiology, radiology, and labs) because causes vary by organ and patient background.

The findings highlight that a granuloma on a biopsy can result from infection, IBD (including Crohn’s disease), or other systemic conditions, so clinicians should pursue appropriate testing rather than assuming a single cause.

For patients: a granuloma on a pathology report is a descriptive finding that can reflect several possible diagnoses; clinical context, additional tests (including microbiology), and sometimes radiology are needed to reach a cause. Discuss with your clinician what further testing is planned if granulomas are reported.

For clinicians and diagnosticians: consider systematic use of microbiological cultures, targeted testing for mycobacteria in higher-risk populations, and integration of clinical origin when interpreting granulomatous inflammation. The low rate of cultures in this cohort suggests a gap in workup.