Presentation
Known diabetic with low grade fever, cough and chest pain.
Patient Data
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Focal contrast-filled outpouching measuring 4.0 x 3.7 x 4.6 cm (TR X AP X CC) seen arising from segmental branch of right pulmonary artery with a rind of soft tissue and cystic air lucencies surrounding the vessel wall.
A cavitary lesion containing air-fluid level and surrounding multiple tiny air cysts. There is surrounding reticular opacity with a denser outer rim creating a bird’s nest
GGO with interlobular septal thickening involving the right lung.
Loculated right pleural effusion.
Case Discussion
Infected mycotic aneurysms are uncommon. The aorta, peripheral arteries, cerebral arteries and visceral arteries are commonly involved. Staphylococcus and streptococcus species are common causative agents. Mycotic aneurysms are pseudoaneurysms without a true wall and carry a high risk of rupture and are associated with significant morbidity and mortality. Common causes include septic emboli from infective endocarditis, direct seeding to an adjacent infectious process or superinfection of an already diseased or aneurysmal artery.
In this diabetic patient, the bird’s nest appearance suggests invasive fungal disease.