Oligometastatic Hepatocellular Carcinoma to the Perirectal Pelvis, a Rare Site of Distant Spread.

Prevention, recognition, and staging of hepatocellular carcinoma (HCC) rely primarily on abdominal imaging. Treatment of HCC varies widely based on tumor stage, lymph node involvement, and metastatic disease along with the patient's functional status. We present an unusual case of isolated extrahepatic HCC metastasis involving a solitary lesion in the pelvis, with no other evidence of viable intrahepatic or extrahepatic disease. The detection of this metastasis was aided by regular surveillance magnetic resonance imaging, alpha-fetoprotein monitoring, and pathological diagnosis. Our case highlights the importance of thoroughly evaluating interval changes on surveillance imaging in HCC.