Fibrin Ring Granulomas in Checkpoint Inhibitor-induced Hepatitis.

Fibrin ring granulomas are an uncommon finding in liver biopsies although they have been described in liver injury secondary to several infectious and noninfectious entities, most notably Q fever. Immune checkpoint inhibitors are recent advances in cancer therapy, and stimulate the immune system to cause antitumoral effects but may also lead to adverse immune events such as hepatitis and colitis. We report 2 patients on combination ipilimumab/nivolumab who developed hepatitis and had fibrin ring granulomas in their liver biopsies.