S1792 Metastatic Hepatocellular Carcinoma Diagnosed on Post-Diverticulitis Colonoscopy

Abstract

Introduction: Acute diverticulitis occurs in 10-20% of patients with diverticulosis. In patients with acute diverticulitis, guidelines recommend performing a colonoscopy 6-8 weeks after resolution of symptoms to rule out an underlying colonic malignancy. Here we present a unique case of metastatic hepatocellular carcinoma (HCC) masquerading as acute diverticulitis in a patient with a history of HCC that has been in remission. Case Description/Methods: A 71-year-old man presented to the emergency room with a 1-week history of generalized abdominal pain and fatigue. Past medical history includes orthotropic liver transplantation in 2014 for hepatitis C cirrhosis and HCC. He has good hepatic function and HCC has been in remission. In the emergency room, vital signs were within normal limits. Complete blood count and comprehensive metabolic panel were unremarkable. Abdominal computed tomography with intravenous contrast revealed acute diverticulitis of the descending colon with a 1.4 cm intramural abscess and 1.1 cm abscess adjacent to the colon. This is new compared to abdominal cross-sectional imaging obtained 10 days before. The liver was reportedly normal without any lesion. He was hospitalized and managed conservatively with bowel rest and intravenous antibiotics. He was discharged a few days later after resolution of his symptoms. Two months later, he underwent a colonoscopy showing a small area of irregular mucosa in the descending colon that was concerning for a possible infiltrative lesion (Figure 1). Biopsies of this area revealed metastatic HCC. There was no evidence of diverticulosis on this exam. Discussion: Guidelines recommend that patients with an episode of acute diverticulitis should undergo colonoscopy 6—8 weeks after the resolution of symptoms to exclude colon cancer. Our patient was surprisingly found to have metastatic deposits of hepatocellular carcinoma despite being in remission. In patients with history of extracolonic malignancies, metastatic deposits should be considered in the differential diagnosis of acute diverticulitis and colonoscopy should be performed after symptom resolution.Figure 1.: Colonoscopy showing a small area of irregular mucosa in the descending colon that was concerning for a possible infiltrative lesion, pathology ultimately consistent with hepatocellular carcinoma.