Incidental Finding of Liver Metastasis in a Case of Pancreatic Adenocarcinoma

Abstract

Exocrine cancer of pancreas is the fourth leading cause of death in the United States. Surgical resection is the only curative treatment option. Contrast enhanced multidetector-row computer tomography (MDCT) is the current modality of choice for the detection of distant metastasis in pancreatic cancer. We present a first ever reported case of an incidental liver metastasis in a patient with pancreatic adenocarcinoma. The patient is a 73 year old Caucasian woman who presented with pruritus and painless jaundice. Past medical history was significant for Hypertension, and Type II Diabetes Mellitus but had no significant surgical history. Social history was negative for tobacco, alcohol, and illicit drug use. Family history was noncontributory. Review of system was negative. Liver chemistry revealed Aspartate Aminotransferase 104 U/L, Alanine Aminotransferase 98 U/L, Alkaline Phosphatase 176 U/L, Total Bilirubin 5.7 mg/dL and albumin 3.9 g/dL. Carbohydrate antigen 19-9 was elevated at 278 u/L. Endoscopic retrograde cholangiopancreatogram showed distal common bile duct stricture. Endoscopic ultrasound showed 25 mm pancreatic head mass. Fine needle biopsy of the mass showed adenocarcinoma. Contrast enhanced CT of pancreas and liver and PET /CT scan for staging was negative for distant metastasis. Case was discussed in multidisciplinary team. Patient underwent Whipple procedure. Surgical pathology was positive for poorly differentiated pancreatic ductal adenocarcinoma with perineural invasion. 6/28 regional lymph nodes were positive for malignancy. Lymph nodes involving celiac access and hepatic artery were negative. Intraoperatively liver parenchyma looked grossly abnormal with ultrasonographic findings of early fibrosis. Random wedge biopsy from lateral segment of the liver was positive for 2 mm pancreatic adenocarcinoma.This case clearly suggests that MDCT/PET-CT can miss distant small metastasis. A pilot study done in 2011 by Holzapfel and Reoser-Erken et.al. showed that diffusion weighted magnetic resonance imaging (DW-MRI) is better than MD-CT for detection of small metastatic lesion, with good histopathological correlation. Hence, we need more studies of same kind in future to consider DW-MRI as a part of staging workup in pancreatic lesions that could potentially change the management of pancreatic adenocarcinoma. In addition, it argues for implementation of neo-adjuvant chemotherapy in surgically resectable localized pancreatic adenocarcinoma.2910_A Figure 1. Contrast enhanced CT with pancreatic protocol. Pancreatic head mass (red arrow)2910_B Figure 2. H&E stain, 400 X original magnification.. Wedge Liver biopsy. Histology diagnostic of pancreatic adenocarcinoma.2910_C Figure 3. PET/CT scan. Pancreatic head mass with Fludeoxyglucose (FDG) uptake. (red arrow head)