Atypical case report of hepatocellular carcinoma mimicking gallbladder cholangiocarcinoma: A diagnostic challenge

Introduction and importance: Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) are the two most common primary hepatic malignancies of distinct origins, but they can present with overlapping clinical and imaging features. Accurate differentiation is crucial, especially as treatment and prognosis differ significantly. This report presents a rare case of HCC mimicking gallbladder CCA, highlighting diagnostic challenges.

A 63-year-old man with diabetes and hypertension presented with progressive jaundice, fatigue, and weight loss. Imaging through CT and magnetic resonance imaging revealed a gallbladder mass that invaded the liver, suggesting CCA of the gallbladder. Surgical exploration and en bloc resection were performed, including bisegmentectomy (IVb and V), cholecystectomy, and lymphadenectomy. Postoperative histopathology revealed a lymphocyte-rich and well-differentiated variant of HCC, not CCA.

Despite the imaging and clinical indications of CCA, histological analysis confirmed the presence of HCC. The case highlights the limitations of imaging in atypical presentations and underscores the value of biopsy in obtaining a definitive diagnosis. The accurate classification of liver malignancies is critical for determining therapeutic strategies, such as eligibility for liver transplantation, and for prognostic accuracy.

This case highlights the diagnostic challenge of distinguishing HCC from CCA when imaging features overlap. Histopathological confirmation remains essential, and a multidisciplinary approach is vital for optimal patient management.