Coexistence of hepatocellular carcinoma and focal nodular hyperplasia in a non-cirrhotic liver: A case report

Introduction and importance: The coexistence of hepatocellular carcinoma and focal nodular hyperplasia in a noncirrhotic liver is rare and diagnostically challenging due to overlapping imaging features. This case report exposes key diagnostic pitfalls and stresses integrating clinical, imaging, and pathology data for accurate diagnosis and management. Case presentation: A 65-year-old woman with chronic hepatitis C and no cirrhosis presented with persistent generalized pruritus. Laboratory tests showed cholestatic liver abnormalities and an elevated alpha-fetoprotein level of 46.6 ng/mL. Computed tomography and magnetic resonance imaging suggested focal nodular hyperplasia, based on typical enhancement and a central scar. Due to discordance between imaging and tumor markers, she underwent resection of liver segment IVb with cholecystectomy. Histopathology revealed the unexpected coexistence of well-differentiated hepatocellular carcinoma adjacent to focal nodular hyperplasia. Clinical discussion: This case highlights the diagnostic challenge of differentiating focal nodular hyperplasia from hepatocellular carcinoma in non-cirrhotic patients. Although focal nodular hyperplasia usually shows distinctive imaging features, well-differentiated hepatocellular carcinoma can closely mimic them. When non-invasive methods are inconclusive, surgical resection may be needed for definitive diagnosis. Conclusions: Clinicians should maintain a high index of suspicion for hepatocellular carcinoma even in noncirrhotic patients presenting with liver lesions suggestive of focal nodular hyperplasia and elevated tumor markers. This case highlights the importance of comprehensive evaluation and the role of surgery in ambiguous hepatic lesions.