case_images: PMC11316590_01
case_images: Painful swelling of the left ankle and left knee.
case_images: acmi-6-00767-g001.jpg
case_images: PMC11316590_01_acmi-6-00767-g001.jpg
case_images: F1
case_images: The skin examination revealed an erythematous, edematous patch on the anterior surface of both ankles and legs with infiltration of the soft tissues of the left leg (Fig. 1).
case_images: MRI of the left knee showing an abscessed collection extending from the subquadricipital recess to the lateral external recess, measuring 22x99 mm, with hypodensity.
case_images: acmi-6-00767-g002.jpg
case_images: PMC11316590_01_acmi-6-00767-g002.jpg
case_images: F2
case_images: Thoracic CT scan showing a pre- and retrosternal collection extending towards the cervicothoracic orifice, measuring 63x74x97 mm, with sternal erosion and the onset of anterior mediastinitis.
case_images: acmi-6-00767-g003.jpg
case_images: PMC11316590_01_acmi-6-00767-g003.jpg
case_images: F3
case_images: Microbiological examination of the joint aspiration. (a) Macroscopic appearance of joint fluid after puncture. A purulent and hemorrhagic fluid in a context of septic arthritis where major synovial inflammation is responsible for intra-articular bleeding. (b) S. pyogenes in cocci short chains, under Gram staining. Their blue color indicates that they are Gram positive. Optical microscope with magnification x100.
case_images: acmi-6-00767-g004.jpg
case_images: PMC11316590_01_acmi-6-00767-g004.jpg
case_images: F4
case_images: Faced with this clinical presentation of left knee arthritis associated with a probable infectious anterior mediastinitis, emergency ultrasound-guided fine needle aspiration of the joints and mediastinum were performed, supplemented by a cyto-bacteriological examination of the samples, revealing a turbid aspect (Fig. 4).