A case of progressing pseudoaneurysm development and potential complications. Pancreatic pseudoaneurysms are a rare, but potentially life-threatening complication of pancreatitis, typically arising when a pancreatic pseudocyst invades or erodes into a neighboring artery. Endoscopic therapy is increasingly utilized for managing pancreatic pseudocysts and Waldorf pancreatic necrosis, WOPN, but the presence of a pseudoaneurysm necessitates a cautious approach to avoid catastrophic bleeding. We present a unique case of a pancreatic pseudoaneurysm embedded within a pseudocyst and the multidisciplinary management approach that led to a successful outcome. A 36-year-old male with a history of alcohol use disorder, tobacco dependence, and opioid use disorder and remission presented with abdominal pain, nausea, and vomiting. Laboratory findings showed leukocytosis, mild anemia, hemoglobin 11.6, and mild electrolyte disturbances. Initial CT imaging demonstrated acute pancreatitis with fluid collections in the pancreatic body 3.1 cm and tail 3.7 cm. Over the next three weeks, the patient's symptoms persisted, with repeat imaging revealing progression to WOPN. Endoscopic ultrasound, EUS, identified a 13 x 33 mm anechoic lesion with internal debris and a suspected pseudoaneurysm, hence drainage was deferred. On follow-up, EUS revealed significant enlargement of the lesion, 47 x 47 mm, with blood products and splenic artery dilation indicative of a 7 mm fusiform aneurysm. Contained bleeding of the splenic artery pseudoaneurysm was suspected, prompting immediate embolization via interventional radiology. The patient, whose hemoglobin had dropped to 5.8 g per deciliter, was admitted to the intensive care unit and subsequently recovered fully. The patient underwent multiple endoscopic evaluations, using EUS and CT imaging for initial and follow-up assessments. The initial EUS revealed a pancreatic pseudocyst containing a pseudoaneurysm, necessitating a deferment of transmural drainage. During a planned outpatient EUS and ERCP for stent placement, a drastic increase in the size and complexity of the pseudoaneurysm was observed, necessitating emergent intervention. This case highlights the importance of careful endoscopic evaluation in avoiding complications during pseudocyst management. Pancreatic pseudoaneurysms represent a critical complication of pancreatitis requiring a high index of suspicion during pseudocyst evaluation. This case highlights the importance of EUS guided imaging to identify pseudoaneurysms before planning invasive procedures, ensuring patient safety, and avoiding life-threatening hemorrhages. Contemporary collaboration is essential for optimal management, with interventional radiology playing a pivotal role in emergent cases.

pancreatic pseudoaneurysm

Waldorf pancreatic necrosis

endoscopic ultrasound

splenic artery embolization

multidisciplinary management