Imaging Assessment of Periaortic Inflammation in Erdheim-Chester Disease.

Reaching etiologic diagnoses for retroperitoneal fibrosis may be challenging. We report the case of a 75-year old male with history of ruptured abdominal aortic aneurysm and subsequent retroperitoneal fibrosis who developed four years later a soft tissue infiltration surrounding the ascending thoracic aorta. Thanks to his medical records and multimodality imaging assessment, the patient escaped an open-chest biopsy through histolgical reassessment of the abdominal periaortic samples that allowed the definitive diagnosis of Erdheim-Chester disease, a rare non-Langerhans histiocytosis.