Delayed diagnosis of acquired hemophilia a complicating hepatocellular carcinoma: a rare case of hepatectomy following atezolizumab and bevacizumab therapy.

Acquired hemophilia A (AHA) is a rare autoimmune bleeding disorder caused by autoantibodies against coagulation factor VIII, leading to reduced activity and prolonged activated partial thromboplastin time (APTT). We report the case of a man in his 60s with alcoholic liver cirrhosis who was referred for hepatic masses detected during surveillance. Imaging revealed hepatocellular carcinoma (HCC) with suspected inferior vena cava invasion, and systemic therapy with atezolizumab plus bevacizumab achieved marked tumor shrinkage and disappearance of vascular involvement. During treatment, the patient developed gingival bleeding with prolonged APTT, which was initially attributed to bevacizumab and not further investigated. After discontinuation of bevacizumab, bleeding resolved, and extended left hepatectomy was performed. Postoperatively, persistent bleeding and a pseudoaneurysm prompted further evaluation, leading to the diagnosis of AHA. Steroid therapy normalized APTT, and the patient recovered without recurrence of bleeding. Pathological analysis revealed moderately differentiated HCC and complete pathological response in one lesion. This case underscores the need to consider AHA in HCC patients with unexplained APTT prolongation, even in the absence of a bleeding history. Careful evaluation of coagulation disorders is critical for the safe management of surgical candidates following immunotherapy.