Ruptured mycotic iliac artery aneurysm presenting as infected psoas haematoma and mimicking psoas abscess

Pseudoaneurysm of the iliac arteries are rarely reported in the literature. Failure to identify the pathology may delay the necessary treatment, and potentially lead to high mortality. We report a case of ruptured mycotic iliac artery aneurysm in a 46-year-old man with newly diagnosed diabetes mellitus. Initial CT appearance mimicked psoas abscess. However, further CT showed features more suggestive of a psoas haematoma with heterogeneous hyperdensities within the lesion. A ruptured mycotic iliac artery aneurysm was diagnosed. Patient was urgently referred to the vascular team for endovascular stenting. Blood-stained purulent material was noted in the left psoas muscle intra-operatively. It was drained and sent for culture, which later yielded Salmonella Enteritidis sensitive to cefotaxime. We present this case to highlight the importance of reviewing any pre-contrast intramuscular hyperdensities which may suggest acute blood content, and raise suspicion of adjacent vascular pathologies.