2502 Rare Hepatic Adenomatosis Diagnosed by Endoscopic Ultrasound-Guided Fine-Needle Biopsy

Abstract

INTRODUCTION: While hepatic adenomas are uncommon (1:100,000), hepatic adenomatosis (HA), defined as >10 adenomas, is even more rare (1-2.4:1,000,000) and poorly understood. HA poses a significant risk of hemorrhage and progression to hepatocellular carcinoma. Diagnosis by percutaneous fine needle biopsy (FNB) poses potential risk of infection and bleeding, and can be made more safely with endoscopic ultrasound FNB (EUS-FNB). Data on safety and efficacy of EUS-FNB in diagnosis of HA is limited, however it has high efficacy in the evaluation of gastrointestinal tumors and solid pancreatic lesions. This rare case of HA highlights the scarcity and risk factors of the condition while presenting a minimally invasive approach for diagnosis. CASE DESCRIPTION/METHODS: A 43-year-old female presented with nausea, vomiting, diarrhea, vague epigastric pain, and unremarkable past medical history with 20-year history of oral contraceptive pill (OCP) use. Laboratory results were significant only for elevated liver function tests and quickly resolving leukocytosis and symptoms. She was diagnosed with uncomplicated gastroenteritis but an abdominal CT incidentally showed multiple hepatic lesions scattered throughout the liver. MRI confirmed diffuse hepatic steatosis and numerous liver lesions (maximum diameter 3.51 cm) (Figure 2), consistent with hepatic adenomatosis vs. metastatic cancer. EUS-FNB was performed with pathology revealing inflammatory type hepatocellular adenoma (HA-I) (Figure 3). DISCUSSION: Although little evidence correlates the development of HA with the use of OCP's, there is a notably higher prevalence in females, consistent with the known association of adenoma and exogenous estrogen. Our patient's female gender and 20-year OCP use are the only currently understood risk factors for her HA. They are structurally composed of an extensive sinusoidal network and have minimal connective tissue covering, expanding the risk of intralesional hemorrhage and hemoperitoneum. Continuing to diagnose this condition through minimally invasive EUS-FNB can further illuminate risk factors for progression as well as aid in the understanding of HA's pathology and risk for malignant transformation and hemorrhage.