The Diagnostic and Follow‐Up Value of Contrast‐Enhanced Ultrasound of IgG4 ‐Associated Hepatic Inflammatory Pseudotumor: A Case Report and Review

ABSTRACT IgG4‐related hepatic inflammatory pseudotumor (IgG4‐HIPT) represents a rare hepatic manifestation of IgG4‐related disease (IgG4‐RD) and is frequently misdiagnosed at initial presentation. We report the case of a 58‐year‐old man with a history of autoimmune pancreatitis (AIP) who presented with incidentally detected multiple hepatic lesions. Serum IgG4 was markedly elevated to 7546.6 mg/L. Contrast‐enhanced ultrasound (CEUS) suggested cholangiocarcinoma, contrast‐enhanced computed tomography (CECT) and magnetic resonance imaging (CEMR) favored hepatic abscesses, while 18 F‐FDG PET‐CT supported an inflammatory process. As the patient declined biopsy, a clinical diagnosis was made based on prior IgG4‐RD, serological findings, and multimodal imaging features, and empirical immunosuppressive therapy was initiated. Subsequent follow‐up demonstrated significant lesion regression. Although histopathological confirmation was unavailable, the constellation of clinical, serological, and imaging findings was consistent with a presumptive diagnosis of IgG4‐related hepatic inflammatory pseudotumor. This case offers important insights into the imaging differentiation and noninvasive management of IgG4‐HIPT.