Lobar pneumonia is usually caused by typical organisms – such as Streptococcus pneumoniae – but may also be caused by atypical organisms – as in this patient
The consolidation obscures the left heart border indicating it is in the adjacent lingula of the left upper lobe
Pneumonia caused by atypical organisms is more common in individuals who are immunocompromised
This patient was immunocompromised due to chemotherapy treatment for leukaemia
Fungal elements were found following bronchoscopy and bronchial washing
Consolidation seen in a non-lobar distribution should raise the suspicion of atypical organisms
This patient with known HIV infection has subtle consolidation in the mid zones bilaterally
Although the consolidation appears minor, this patient was extremely unwell with low oxygen saturation which worsened on minor effort (walking down the ward)
Pneumocystis pneumonia (PCP) was the diagnosis in this case
Note: Initially the chest X-ray can be entirely normal in patients with PCP