2202 Liver Mass in Cirrhotic Patients: Is It Always Hepatocellular Carcinoma (HCC)?

Abstract

INTRODUCTION: Pancreatic acinar cell carcinomas (PACCs) comprise only 1-2% of all pancreatic cancers. Patients with PACC have a prognosis better than pancreatic ductal adenocarcinomas but worse than pancreatic neuroendocrine tumors. They are easier to differentiate from the prior, but may have many similar morphological features to the latter. The majority of pancreatic tumors are adenocarcinomas of the ductal type; and carcinomas with multiple lineage differentiation are extremely rare. We present a rare case of PACC with neuroendocrine differentiation. CASE DESCRIPTION/METHODS: 51-year-old male with history of chronic Hepatitis B infection, liver cirrhosis (CPT class B, MELD 15) was admitted for abdominal pain, leg swelling and worsening renal function. Pertinent physical exam revealed a tense abdomen and diffuse tenderness. An abdominal non-contrast computed tomography (CT) scan revealed a large cm ill-defined mass in the central liver involving both right and left liver lobes. A large mass medial to the splenic hilum measuring approximately 8.7 × 6.8 cm, abutting the stomach, pancreas and spleen was also seen. An Endoscopic Ultrasound (EUS) confirmed an anechoic splenic hilum mass measuring 8 cm in greatest dimension. A 2.4 cm × 2.2 cm anechoic left liver lobe mass was also appreciated. Fine needle aspiration (FNA) was performed for each of these masses. Histopathology revealed acinar-cell carcinoma with neuroendocrine differentiation. Positive Periodic acid-Schiff (PAS), Trypsin and Chromotrypsin stains on immunohistochemistry (IHC) supported the acinar differentiation. Positive synaptophysin and chromogranin stains supported neuroendocrine differentiation. Diagnosis of pancreatic neoplasm with metastasis to the liver was made and patient was referred to an oncologist. DISCUSSION: Forming the diagnosis of a mixed carcinoma requires thorough assessment of individual components in the tumor. Current theories suggest their origin from a stem cell with propensity for multi-directional differentiation. Close morphological examination and immunohistochemical staining are fundamental in making an accurate diagnosis. Better understanding of prognosis and treatment of pancreatic tumor with multi-lineage origin requires evaluation of additional cases due to their paucity.