LAUSR

© Author(s) (or their employer(s)) 2022. No commercial reuse. See rights and permissions. Published by BMJ. RN: SPECIALTY TRAINEE IN RESPIRATORY MEDICINE A 52yearold woman presented to the emergency department (ED) with a 1week history of right lower chest and upper quadrant pain and sore throat. She also reported a 2day history of fever, rigours and productive cough. Her medical history was significant for chronic obstructive pulmonary disease with a significant smoking history of 51 packyears. Regular medications included tiotropium, seretide/fluticasone and ventolin. On initial examination, she was hypotensive (blood pressure 95/60 mm Hg), tachycardic (heart rate 104 bpm) and febrile (temperature 38.2°C). There were no stigmata of infective endocarditis on inspection of the peripheries. An erythematous, fluctuant, tender swelling measuring 2–3 cm in diameter was present in the left submandibular region. Chest auscultation revealed coarse crackles at the right lung base. Her abdomen was soft and nontender. Blood tests showed elevated white cell count (WCC) 26.5×10 /L and Creactive protein (CRP) 295 mg/L and an acute kidney injury (creatinine 113 μmol/L). A chest Xray (CXR) (figure 1) demonstrated a rightsided pleural effusion with multiple rounded opacities bilaterally. While in ED she was treated with intravenous fluids and initial doses of intravenous broadspectrum antibiotics. The patient went on to have a CT scan of the chest, abdomen and pelvis (figure 2), given concerns about sepsis with an unclear source, abdominal pain, the cause of which was also uncertain and the abnormal CXR. VD: SPECIALTY TRAINEE IN CLINICAL RADIOLOGY The CT scan showed bilateral lung lesions, many demonstrating a reversed halo sign (thick walled lesions with central ground glass opacification) or central cavitation as well as several rightsided peripherally enhancing pleural collections containing gas locules (figure 2). The described lesions were felt likely to all be secondary to a single common aetiology. Lung lesions with a reversed halo sign have a relatively wide differential including bacterial pneumonia, invasive fungal infection, cryptogenic organising pneumonia, pulmonary infarction, granulomatosis with polyangiitis and neoplasm among others. The main differential for the described pleural collections is empyema. RN: An ultrasound (US)guided diagnostic thoracocentesis was performed and the pH of the pleural fluid was noted to be 6.8, consistent with pleural infection. The operator at the time was unable to proceed with chest drain insertion due to the complex nature of the pleural collection. Following discussion with the microbiologist, the patient was initiated on intravenous tazocin (piperacillin with tazobactam), teicoplanin and metronidazole. She was admitted to the intensive care unit for inotropic support and closer monitoring, where she remained for 6 days. Her case was discussed at the thoracic imaging meeting and the consensus was that although underlying malignancy could not be fully excluded, the imaging and clinical history was more consistent with an infective process. Figure 1 AP chest Xray demonstrating bilateral rounded opacities and a rightsided pleural effusion). AP, anteroposterior. Figure 2 Axial sections from postcontrast CT chest. Lung window images (A, B) show bilateral lung lesions, one of which demonstrates the reversed halo sign. Softtissue window images (C, D) show rightsided peripherally enhancing pleural collections containing gas locules.