A 54-year-old man consulted for low back pain of 5 weeks of evolution, refractory to regular analgesics, and significant weight loss. The PET-CT revealed a retroperitoneal mass in contact with the anterior wall of the abdominal aorta. After consulting with the Endoscopy Unit, an endoscopic ultrasound-guided FNAP was performed due to the accessibility of the lesion and the less invasive nature of these procedures. The anatomopathological result was angiosarcoma of the aorta.