The Wandering Pancreas: A Rare Case of Complex Hiatal Hernia Presenting With Thoracic Symptoms.

Hiatal hernia (HH) is defined as the protrusion of abdominal contents through the esophageal hiatus of the diaphragm into the mediastinum. While type I sliding hernias are common, type IV hernias, which are characterized by the herniation of organs other than the stomach, such as the colon or spleen, are uncommon. Even more exceptional is the herniation of the pancreas, given its retroperitoneal fixation. We report the case of a 60-year-old female with a history of obesity (BMI 32 kg/m²) who presented with a six-month history of chronic dry cough, dyspnea, and retrosternal heaviness. Initial chest radiography revealed a retrocardiac opacity with an air-fluid level that mimicked a mediastinal mass. Urgent multidetector CT (MDCT) showed a giant type IV HH (defect size 5.5 cm) containing the stomach, transverse colon, and notably, the body and tail of the pancreas. The diagnosis was confirmed by identifying the characteristic "collar sign" and "vascular looping" of the splenic vessels and left gastric artery extending into the thorax. Although the patient did not display signs of acute pancreatitis or obstruction, the large defect size and vascular involvement necessitated a surgical referral to prevent future incarceration. This report highlights the critical role of MDCT in identifying the "vascular loop" sign, which helps distinguish pancreatic herniation from mediastinal neoplasms and avoid iatrogenic injury during surgical repair.