Hematogenous metastasis to the colon from hepatocellular carcinoma: A case report.

Introduction and importance: Most extrahepatic metastases of hepatocellular carcinoma (HCC) are to the lungs and bones, metastases to the colon are rare. In the present study, we experienced a case of metastasis to the ascending colon during repeated treatment for HCC. Case Presentation: A 63-year-old man was diagnosed with multiple HCCs (T4N0M0 stage IIIB) associated with portal vein invasion. Transcatheter arterial chemoembolization (TACE), transarterial infusion (TAI) and radiofrequency ablation (RFA) were performed, and partial response was achieved, but the main nodule at S6 lesion subsequently recurred to protrude outside of the liver. A partial hepatic S6 resection was performed for local control 1.5 years after the initial treatment. IVR was then performed again, but approximately 8 months after hepatic resection, an abdominal computed toography (CT) showed a mass lesion in the ascending colon. After a total colonoscopy and biopsy, a diagnosis of colorectal metastasis of HCC was made. A right hemicolectomy was performed for local control. The patient had a good post-operative course, but developed liver failure due to rapid growth of the tumor thrombus of the main portal vein and died of primary disease approximately 3.5 months after the colon resection. Clinical Discussion: The metastasis of HCC to the colon is an extremely rare occurrence. Conclusion: One possible reason for this rarity is that portal vein tumor thrombosis (PVTT) results in colorectal metastasis via trans-portal retrograde metastasis.