A Rare Case of Metastatic Hepatocellular Carcinoma to the Colon with Associated Paraneoplastic Syndrome

Abstract

Purpose: Hepatocellular carcinoma (HCC) is an aggressive malignancy with poor prognosis that is associated with a 4-6 month mean survival. Early detection with surgical resection offers the best chance for long-term survival. There are rare cases of patients with extrahepatic HCC recurrences. We report an unusual case of extrahepatic HCC occurring 18 and 36 months following initial presentation. Results: A 79-year-old man presented with 1 month of persistent epigastric pain. An abdominal CT revealed a large (16.5 × 13.8 cm), lobulated mass in the left hepatic lobe. Hepatitis B and C serology were negative. An alpha feto-protein (AFP) was 123 ng/mL. A left hepatic lobectomy was performed. Pathology revealed a high grade hepatocellular carcinoma. Surveillance included serial AFPs (which had normalized) and regular CT scans. Sixteen months after hepatic resection, he had a gastric outlet obstruction. An abdominal CT revealed a large (8.4 × 8.1 cm) exophytic gastric mass. An AFP was 23 ng/mL. An EGD with EUS revealed a retrogastric mass with cystic components. FNA obtained necrotic tissue and tumor fragments consistent with metastatic HCC. A distal gastrectomy with roux gastrojejunostomy was performed. Pathology revealed a poorly differentiated carcinoma consistent with the primary HCC. He remained clinically stable for 18 months when an abdominal CT revealed a mid-transverse colon mass. A colonoscopy performed prior to the hepatic resection removed 5 diminutive tubular adenomas. A repeat colonoscopy revealed a partially obstructing, malignant appearing mass. Biopsies revealed a poorly differentiated carcinoma consistent with metastatic HCC. Additionally, biopsies of the nodular mucosa in the cecum revealed lamina propria, intraepithelial and muscularis mucosal eosinophils. The peripheral eosinophil count was 24%. A transverse colectomy with primary anastomosis was performed. The specimen was described as an eccentric fungating lesion involving the full thickness of the bowel with gross invasion of the pericolic fat. There were no other intra-abdominal masses or liver metastases. Conclusion: This is a rare case of extrahepatic HCC metastases occurring at 18 and 36 months following hepatic resection. Gastrointestinal involvement of HCC is highly unusual, occurring in 0.5-2% of cases. The most common site of GI involvement is the duodenum, followed by stomach and least often colon. The presumed mode of transmission is direct invasion of the GI tract. However, hematogenous spread to the colon has been speculated and is thought to have occurred in this patient. Awareness of the unusual occurrence of extrahepatic metastatic HCC is important to ensure adequate surveillance following primary resection.