Hepatopulmonary Syndrome Associated With Metabolic Dysfunction-Associated Steatotic Liver Disease in a Patient With Interstitial Pneumonia and COPD.

Hepatopulmonary syndrome (HPS) is a rare pulmonary vascular complication of liver disease characterised by impaired oxygenation due to intrapulmonary vascular dilatation. Herein, we report a case of HPS associated with metabolic dysfunction-associated steatotic liver disease (MASLD) in a patient with interstitial pneumonia and chronic obstructive pulmonary disease. The patient presented with progressive hypoxemia and the radiological findings were disproportionate to the degree of oxygen desaturation. Imaging and Tc-99 m MAA lung perfusion scintigraphy confirmed the presence of an intrapulmonary right-to-left shunt. Liver imaging revealed MASLD-related cirrhosis and the patient later developed drug-induced hypersensitivity syndrome (DIHS) with cytomegalovirus reactivation and hepatic dysfunction. Following antiviral therapy and supportive management, oxygenation partially improved, whereas hypoxemia remained disproportionate to radiological lung findings, consistent with hepatopulmonary syndrome. Transplantation was considered but unavailable, and the patient remained under observation. This case highlights that MASLD-related systemic inflammation can predispose patients to HPS and that careful hepatic evaluation is crucial in DIHS.