A giant left internal iliac artery aneurysm in a patient with Loeys-Dietz syndrome.

A 16-year-old female presented with left iliac fossa pain. In January 2021, she was admitted to her local hospital with severe lower abdominal pain and the pelvic ultrasound demonstrated a 13-cm left internal iliac artery dissecting aneurysm with its partial thrombosis. On examination, she had a high-arched palate, multiple skin stretch marks, flat feet and a soft systolic ejection murmur at the left 5th mid-clavicular line. She had a mildly tender abdomen in the left iliac fossa. Computed tomography angiography demonstrated a 12.2 cm × 10.4 cm × 12.5 cm left internal iliac artery aneurysm. During surgery, the aneurysm was incised and the proximal and distal orifices of the internal iliac artery were ligated. Genetic testing yielded 2 mutations in the SMAD3 gene characteristic for Loeys-Dietz syndrome.