Fig. 1
figure 1

A 6 × 5 cm mediastinal abscess arising from bilateral sternoclavicular septic arthritis, consistent with descending cervical infection. A 67-year-old woman presented with mild neck pain and blurred vision, diagnosed as anterior uveitis. Blood tests revealed severe leucocytosis, CRP 472, AKI, and deranged LFTs. She re-attended with worsening neck pain, neurological deficits, and confusion. MRI showed cervical paravertebral and anterior epidural collections causing cord compression (C2–C6), multifocal lumbar facet effusions, right L2/L3 epidural collection, and a retropharyngeal abscess. An axial CT scan confirmed a 6 × 5 cm mediastinal abscess arising from bilateral sternoclavicular septic arthritis, consistent with descending cervical infection. Blood cultures grew Staphylococcus aureus. Management included IV antibiotics, ophthalmic care for endophthalmitis, and multidisciplinary planning for sternoclavicular joint abscess drainage with cardiothoracic and orthopaedic teams. Conservative management was chosen for spinal involvement. Prognosis highlighted that antibiotics alone are inadequate for mediastinal infections, reinforcing the need for surgical drainage in such cases.