INTRODUCTION: Pancreatic adenocarcinoma is one of the most malignant and aggressive cancers, accounting for over 400,000 deaths annually. Classically, computed tomography (CT) is adequate in the diagnosis of pancreatic adenocarcinoma, with a reported sensitivity of up to 96%. This case describes an extremely unique presentation of pancreatic adenocarcinoma in a young female. CASE DESCRIPTION/METHODS: A 36-year-old female with history of iron deficiency anemia with several month history of abdominal pain and distention with associated non-bloody diarrhea. The patient also endorsed fifty pounds of unintentional weight loss. The patient had a hemoglobin of 8.8 mg/dL and a serum ferritin of 2 ng/mL. Her chemistries and liver function tests were within normal limits. A CT scan of the abdomen showed a large retroperitoneal mass encasing the celiac trunk and branchpoint of the superior mesenteric artery with associated retroperitoneal fibrosis. Additionally, there was chronic thrombosis of the splenoportal confluence and associated pelvic congestion syndrome and a moderate amount of abdominal ascites. MRI showed extrahepatic common bile duct stricture with proximal dilation and two cystic lesions in the neck of the pancreas with ductal dilatation. The patient subsequently underwent CT-guided retroperitoneal lymph node biopsy which only showed dense fibrous tissue consistent with retroperitoneal fibrosis. On EUS, an FNA of the pancreatic cyst was positive for pancreatic adenocarcinoma. Unfortunately, given the patient’s advanced disease, the patient was not a candidate for chemotherapy and was ultimately referred for palliative care. DISCUSSION: This case uniquely describes a case of pancreatic adenocarcinoma presenting as retroperitoneal fibrosis (RF). RF is most commonly idiopathic, accounting for up to 75% of cases. However, autoimmune processes such as immunoglobulin-G4 mediated disease have been implicated in its pathogenesis. Notably, there have been no significant associations between RF and pancreatic malignancies. This case highlights the importance of maintaining a high index of suspicion for malignancy in the differential for retroperitoneal fibrosis. Diagnosis in this patient was complicated by the proximity of the fibrotic tissue to the major branches of the aorta including the celiac trunk and superior mesenteric artery. However, definitive diagnostic modality such as EUS and FNA should not be delayed, especially in the presence of pancreatic masses.