Case Report: Radiological-Pathological Correlation of Ectopic Pancreatic Tissue as Anterior Mediastinal Mass

Ectopic pancreatic tissue presenting as large anterior mediastinal mass is exceedingly rare and poses a significant diagnostic challenge, which could mimic common malignancies such as thymoma, teratoma or lymphoma. We report a case of a 49-year-old female who presented with pleuritic chest pain, new-onset atrial fibrillation with rapid ventricular response and nonsustained ventricular tachycardia. Computer tomography pulmonary angiogram (CTPA) identified a large peripherally enhancing anterior mediastinal mass with extensive central necrosis. The lesion exerted a significant mass effect, compressing the pulmonary trunk and displacing the ascending aorta. Initial CT-guided core biopsy was nondiagnostic, yielding only necrotic debris and neutrophils. Given the diagnostic uncertainty and the patient's worsening symptoms, a surgical biopsy via a Chamberlain procedure was performed, revealing thick, black necrotic fluid with histology confirming ectopic pancreatic tissue. This case demonstrates ectopic pancreatic tissue as a rare differential of a necrotic anterior mediastinal mass. Early recognition is vital to guide appropriate surgical management and prevent morbidity related to pancreatic enzymatic action on surrounding key anatomical structures and the misdiagnosis of more common mediastinal neoplasms.