A 74-year-old female with a 15mm spiculated nodule who underwent VATS right upper lobectomy. An unsuspected paratracheal mass was identified intraoperatively below the arch of the azygos vein (Fig. 1A). Any abnormally enlarged lymph nodes had been reported in the computed tomography scan preoperatively. However, given the suspicion of N1 disease, biopsy was performed leading to rupture and bleeding of what turned out to be an aneurysm of the azygos vein. Bleeding was easily controlled by VATS. The patient was extubated and transfer to the ICU. Postoperative course was uneventful and the patient was discharge in the 4th postoperative day. Pathological analysis was consistent with a moderately differentiated squamous cell carcinoma pT1aN0M0. Postoperative review of the images confirmed the presence of a saccular aneurysm (19mm×11mm) in the proximal end of the arch of the azygos vein (Fig. 1B).
Aneurysms of the azygos vein are very infrequent vascular malformations. Patients are usually asymptomatic, although complications such as thrombosis, rupture or compression of adjacent organs have been described.1 Small and saccular aneurysm of the azygos vein can simulate a pathological lymph node,2 especially in the context of oncological surgery, and preoperative identification can be challenging.
