1458 Colon Cancer Metastatic to the Pancreas Presenting as DKA

Abstract

INTRODUCTION: New onset diabetes mellitus (DM) in the setting of a pancreatic mass has been described, primarily with adenocarcinomas, due to the secretion of diabetogenic substances. DM related to pancreatic metastases is rarely seen. We present a case of colon cancer metastatic to the pancreas presenting as diabetic ketoacidosis (DKA). CASE DESCRIPTION/METHODS: A 69-year-old male with a 70 pack-year tobacco history and hypertension presented to the emergency department with fatigue, weight loss, and abdominal pain. Laboratory tests demonstrated a white blood cell count of 11.8 109/L, a hemoglobin of 8.0 g/dL, sodium of 125 mmol/L, carbon dioxide of 18 mmol/L, and a glucose of 656 mg/dL with positive serum ketones indicating diabetic ketoacidosis. He was admitted to the hospital and treated with insulin and IV crystalloids. A chest x-ray showed multiple lung nodules. A CT scan of the chest, abdomen, and pelvis revealed bilateral lung masses, an uncinate process pancreatic mass, multiple hypodense liver lesions, and thickening of the sigmoid colon. Bronchoscopy was performed and cytology revealed metastatic adenocarcinoma with suspected source of colonic, hepatobiliary, or upper gastrointestinal source. EUS/FNA was performed on the pancreatic mass and demonstrated poorly differentiated carcinoma of unclear primary source. Flexible sigmoidoscopy discovered a friable mass in the sigmoid colon. Biopsies were taken revealing adenocarcinoma on the background of high grade dysplasia consistent with a primary colon cancer. Given the widely metastatic nature of his disease he was offered FOLFOX + Bevacizumab as well as a palliative care referral. DISCUSSION: The majority of malignant pancreatic lesions are primary pancreatic tumors, with a small percentage due to metastases. The most common tumor to metastasize to the pancreas is renal cell carcinoma. Few cases of metastatic colon cancer to the pancreas have been reported. DKA as a first presentation of pancreatic adenocarcinoma is a very rare phenomenon with more typical presenting symptoms including abdominal pain, nausea and jaundice. Our case features two rare findings; metastatic colon cancer to the pancreas and DKA as the initial presentation of a pancreatic mass. This highlights the need to consider uncommon metastatic lesions in cases of symptomatic pancreatic masses.