Poorly differentiated signet ring cell carcinoma of pancreas masquerading as chronic pancreatitis

Abstract

Pancreatic cancer is typically arises in the context of inflammation, and a surrounding area of pancreatitis is often present within the tumor microenvironment. Signet ring cell carcinoma (SRCC) is a rare variant of pancreatic adenocarcinoma. Pathologically, it presents either as single cells or loose clusters masquerading in the background of pancreatitis. Sampling of these inflammatory cells during biopsy can result in the incorrect diagnosis of pancreatitis. We report a case of SRCC of the pancreas which the diagnosis of cancer was delayed because multiple biopsies revealed only inflammatory changes with no obvious evidence of malignancy. This case highlights the fact that negative results with endoscopic ultrasound fine needle aspiration in SRCC can be misleading. A cancer diagnosis should still be considered despite findings of inflammatory pancreatitis if the clinical presentation is concerning for cancer (mass on CT scan).