Sarcomatoid Carcinoma of the Pancreas: An Unusual Cause of Abdominal Pain

Abstract

Introduction: Sarcomatoid carcinoma of the pancreas (SCP) is a rare and highly malignant variant of pancreas carcinoma that usually has a very poor prognosis. Epithelial-mesenchymal transition (EMT), a transition between different phenotypes, is regarded as an essential process in tumor progression. When EMT occurs, epithelial tumor cells lose their restricted phenotypes, concomitant with the loss of epithelial characteristics and the acquisition of motile behavior. These changes, which contribute to the transition from an epithelial morphology towards a more mesenchymal fibroblastic phenotype, have been reported to occur in some special tumors, such as cholangiocarcinomas; this change is also defined as sarcomatous change. Case Report: A 37-year-old-female with a history of hypertension presented to the hospital with the chief complaint of epigastric abdominal pain. Her abdominal pain progressively worsened and she came back to the hospital 3 weeks later. She also complained of pale, foul-smelling, floating stools that began 3 days prior to presentation with a decrease in her appetite. Routine laboratory showed: hemoglobin, 12.8 g/dL; WBC, 5,100 cells/uL; platelet, 244,000/mm3; with elevation in AST, ALT, alkaline phosphatase; total bilirubin, 4.0 mg/dL; direct bilirubin, 3.1 mg/dL; and LDH 306 u/L and negative viral markers. Tumor marker assays showed elevated CA19-9. Results: CT abdominal scan showed a hypoechoic mass in the uncinate process of the pancreas (Figure 1) with intrahepatic biliary ductal dilatation and dilation of the proximal common bile duct (CBD). The patient underwent an esophagogastroduodenoscopy with brush biopsies of the CBD with stent placement, as well as, an endoscopic ultrasound fine needle aspiration of the pancreatic mass. The patient underwent a pancreaticoduodenectomy to help diagnosis and remove the tumor. The histopathological diagnosis was as follows: ductal adenocarcinoma with sarcomatoid features with the invasion of the tumor in the extra-pancreatic common bile duct, stage IIB (Figure 2A & 2 B).1372_A.tif Figure 1: CT abdomen with contrast showing the hypoechoic mass in the head of the pancreas with intrahepatic biliary ductal dilatation.1372_B.tif Figure 2: Pathology specimen showing adenosquamous carcinomaDiscussion: Adenosquamous carcinoma of the pancreas is associated with high rates of recurrence and metastasis and carries a poor prognosis, much worse than even that of pancreatic adenocarcinoma, which has a reported median overall survival of no more than 5 months. SCP is a rarely appreciated subset of pancreatic malignancy that does not necessarily portend to a uniformly dismal prognosis.1372_C.tif Figure 3: Sarcomatous changes.