A man with culture sterile cavitating lung lesions: molecular techniques can provide the key to diagnosis.

A 20-year-old male presented to the Emergency Department with pyrexia, dyspnoea, chest pain and haemoptysis. Cavitating lung lesions were noted on chest X-ray and the patient was admitted to the intensive care unit where he was intubated and ventilated. Routine investigations including serial cultures did not provide an aetiological diagnosis.