Periaortic lymphoma as a mimic of posttraumatic intramural hematoma.

Computed tomography (CT) of an 87-year-old man who presented to the emergency department with chest pain after a motor vehicle collision demonstrated multiple broken ribs and a thoracic periaortic soft tissue mass which was high density on precontrast images and enhanced postcontrast. The scan also demonstrated a mass encircling the left ureter and masses in the axilla and pelvis. The enhancement of the periaortic lesion and the presence of the additional soft tissue masses suggested lymphoma as opposed to intramural hematoma (IMH). The diagnosis of follicular B-cell lymphoma was rapidly confirmed with fluorodeoxyglucose-positron emission tomography/CT and excisional biopsy of the axillary lymph node. While this is an atypical presentation, lymphoma and other extravascular pathology must be considered in the evaluation of a periaortic high attenuation mass seen on CT.