S5402 Inflammation Situation: Inflammatory Pseudotumors of the Liver

Introduction: Inflammatory pseudotumors of the liver (IPTL) are non-malignant collections of myofibroblastic spindle and inflammatory cells that can mimic malignancies.1 They represent 0.7% of all liver masses.1 We present a case in which suspected metastatic cholangiocarcinoma was found to be IPTL. Case Description/Methods: A 22-year-old woman with a 6-month history of choledochocele and alcohol abuse presented with 2 months of abdominal pain, fevers, and anorexia. Surgical history includes cholecystectomy, hepaticojejunostomy, and a percutaneous transhepatic cholangiography (PTC) drain for management of choledochocoele complicated by recurrent cholangitis. Liver labs noted AST 99 U/L, ALT 71 U/L, alkaline phosphatase 878 U/L, Tbili 0.6 mg/dL, and international normalized ratio 1.2. Viral and serological causes of liver injury were negative. A liver abscess was found in the caudate lobe/segment I and managed with antibiotics. A computed tomography and MRI with and without contrast found an 8.5 cm lesion at the hepatic hilum and a 2.1 cm satellite lesion. The patient was referred to a multidisciplinary tumor board which led to a liver and lymph node biopsy. Pathology revealed benign-appearing cells associated with inflammation. This favored IPTL due to infection. Management included levofloxacin + metronidazole. Four weeks later, the main lesion decreased to 5.8 cm on imaging. Discussion: The mechanism behind IPTLs is unknown.1–3 Possible etiologies are infection, autoimmune disease, trauma, surgery, or chronic biliary obstructions.1–3 They are difficult to diagnose given the non-specific symptoms and malignant appearance.1,2 No standard treatment exists, but strategies can include anti-inflammatories, antibiotics, or surgery.1–3 This case demonstrates that accurate diagnosis of IPTLs is crucial because it can alter treatment from aggressive medical or surgical intervention to conservative management. References 1. Barabino M, Piccolo G, Tramacere A, et al. Inflammatory pseudotumor of the liver or intrahepatic cholangiocarcinoma, that's the question: A review of the literature. Cancers (Basel). 2024;16(17):2926. 2. You Y, Shao H, Bui K, et al. Epstein-Barr virus positive inflammatory pseudotumor of the liver: report of a challenging case and review of the literature. Ann Clin Lab Sci. 2014 Fall;44(4):489-98. 3. Bae SK, Abiru S, Kamohara Y, et al. Hepatic inflammatory pseudotumor associated with xanthogranulomatous cholangitis mimicking cholangiocarcinoma. Intern Med. 2015;54(7):771-5.