Rare case of hepatocellular carcinoma metastasis to urinary bladder: A case report

BACKGROUND: Hepatocellular carcinoma (HCC) is a primary liver cancer with high prevalence and mortality. There are many cases of advanced HCC at the time of diagnosis. Treatment methods and prognosis are different depends on whether metastasis is present. Thus, it is necessary to make an accurate evaluation at the time of diagnosis. Extrahepatic metastases of HCC usually occur through hematogenous spread or through adjacent organs such as the peritoneum. Metastasis to the urinary bladder alone is rare. Here, we report a rare case of biopsy-proven solitary metastasis of HCC to the bladder in a 60-year-old woman. CASE SUMMARY: A 60-year-old female patient was found to be positive for hepatitis B surface antigen by chance after abdominal ultrasonography showed abnormal findings. Thus, liver dynamic computed tomography (CT) was performed. The patient visited the hospital for further examination. Ultrasound and CT showed 3.6 cm sized arterial enhancing mass in segment 5 and an infiltrative mass in segment 8. The patient was diagnosed with HCC through liver dynamic magnetic resonance imaging and liver biopsy. Afterwards, she underwent two transcatheter arterial chemoembolizations within five months for HCC. During follow-up, a newly appeared bladder tumor was found on liver dynamic CT. She underwent transurethral resection of the bladder tumor for diagnosis and treatment. The tissue was confirmed as metastatic HCC. CONCLUSION: Although rare, metastasis to urinary bladder from HCC can occur without evidence of other distant metastases. Thus, regular follow-up imaging examination and clinical attention are required.