Abstract
Ductal adenocarcinoma of the pancreas is the most common pancreatic cancer, but undifferentiated carcinoma of the pancreas with osteoclast-like giant cells (UC-OGCs) is an exceedingly rare tumor. Microscopically, this tumor is characterized by the presence of two different cellular elements, namely, spindle or ovoid mononuclear cells and osteoclast-like giant cells (OGCs). Here, we report a rare case of UC-OGCs in a 79-year-old male with a one-month history of epigastric abdominal pain and unintentional weight loss. A blood workup revealed new-onset type 2 diabetes mellitus, and a computed tomography scan of the abdomen showed acute pancreatitis with a hypodense lesion in the head of the pancreas concerning for malignancy. He underwent an endoscopic ultrasound that also revealed a mass in the head of the pancreas, but no lymphadenopathy was observed. Biopsy was obtained and histopathology revealed UC-OGCs. We present this case to increase awareness of this rare clinical entity in patients presenting with acute-onset pancreatitis.