A Case of Periaortic Lymphoma Mimicking Complicated Type B Acute Aortic Dissection: A Pitfall in the Endovascular Surgery Era.

We report a case of periaortic lymphoma mimicking Stanford type B acute aortic dissection treated for impending rupture by thoracic endovascular aortic repair. Although no endoleak was detected, the aneurysm enlarged continuously. Repeat computed tomography scans showed that an aortic aneurysm-like structure around the stent graft had enlarged irregularly. Histopathological examination revealed diffuse large B-cell malignant lymphoma. Post-chemotherapy, the aneurysm-like structure disappeared without any fistula or rupture. In open surgery, differentiating between aneurysms and malignancy is easy under direct vision; however, in the endovascular surgery era, this is a pitfall because no surgical specimen of the lesion can be obtained.