PMC9152446_01
Maximal intensity projection (MIP) of multi-planar reconstruction computed tomographic angiography at admission day. Multiple septic embolic lesions appearing as nodules are present predominantly in the subpleural as well as peribronchovascular area, while close topographic proximity to the branching pulmonary arteries is noted.
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F1
This revealed signs of pyelonephritis, a renal vein thrombosis and bilateral subsegmental lung emboli co-localizing with multiple round and wedge-shaped infiltrates and a large consolidation in the right lower lobe (Figures 1, 2).
Infectious aneurysm of the pulmonary artery. The initial computed tomography was performed on the day of admission (A) with solely consolidation in the right basal lobe and an accentuated right lower lobe pulmonary artery. Over the course of 20 days an infectious pulmonary arterial aneurysm manifested with a diameter >4 cm (B), coinciding with clinical signs of hemoptysis.
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F2
This revealed signs of pyelonephritis, a renal vein thrombosis and bilateral subsegmental lung emboli co-localizing with multiple round and wedge-shaped infiltrates and a large consolidation in the right lower lobe (Figures 1, 2). Diagnosis of an infectious aneurysm secondary to the initial infection was assumed (Figures 2, 3).
Overview on the clinical course and therapeutic management. With WBC, White blood cell count (red line) and Glc, Serum Glucose (black line) assessed by point of care testing. Duration of the applied antibiotic regimen is indicated by arrow length. Computer tomographic angiography of the thorax was performed twice, revealing progressive intrapulmonary infection of the right pulmonary subsegmental artery with manifestation of an infectious aneurysm (compare Figure 2).
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F3
Following targeted therapy, the patient's vigilance and oxygenation status markedly improved, but glycemic control remained challenging even under a continuously intensified insulin regimen (Figure 3). Diagnosis of an infectious aneurysm secondary to the initial infection was assumed (Figures 2, 3). Upon diagnosis, antibiotic treatment was switched to meropenem (Figure 3), to empirically cover pathogenic resistance mechanisms, that may have manifested under the prolonged prior antibiotic regimen, in order to prevent pathogen related aneurysmal rupture.
Histopathology of the infectious aneurysm of the inferior lobe pulmonary artery and concomitant necrotizing bronchopneumonia. Tissue sections were acquired from the resected right lower lobe comprising the infectious aneurysm. Histopathological work-up was performed with Hematoxylin-Eosin (A,C) and Elastica van Gieson (B) staining. In (A) depicted two magnifications show a dilated pulmonary artery branch occluded by a granulocyte rich fibrin thrombus with accompanying vascular wall necrosis. (B) Highlights the same area in a trichrome staining revealing the dual elastic fiber network. (C) Shows the partially necrotizing, fibrinous-purulent pneumonia adjacent to the vascular changes. Meanwhile, no signs of malignancy were noted in the investigated specimen.
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F4
However, necrotizing and fibrinous purulent, partly gangrenous thromboembolic inflammation was noted (Figure 4).