Unmasking Pancreatic Cancer: A Rare Case of Diabetic Ketoacidosis in a Patient with Type 3c Diabetes Mellitus, Diagnosed by Endoscopic Ultrasound

We report the case of a 55-year-old male patient who presented with an acute one-day history of confusion and disorientation of one-day duration. The patient was dehydrated and in hypovolemic shock. After being diagnosed with diabetic ketoacidosis (DKA) (he did not have any prior history of diabetes mellitus, or any previous history of significant abdominal pain) he was transferred to the ICU. Extensive work up was done to diagnose the primary etiology of DKA. An MRI imaging of the abdomen and pelvis showed diffusely swollen pancreas, indicating chronic pancreatitis along with multiple hyper enhancing scattered foci in distal pancreatic body and tail. Endoscopic ultrasound (EUS) was subsequently performed revealing a lesion suggestive of either chronic focal pancreatitis versus pancreatic neoplasm. An EUS-guided fine-needle biopsy (EUS-FNB) was performed for histopathological correlation, which confirmed a final diagnosis of pancreatic adenocarcinoma. The patient's condition was therefore classified as Type 3c diabetes mellitus, secondary to the malignancy. DKA is a common medical presentation, but a thorough workup is essential to identify its underlying etiology. Pancreatic malignancy should be considered as a rare, but critical, underlying cause.