On hospital day 2, CT of the chest found a rounded opacity in the right lower lobe (figure 1B); the remainder of the lungs appeared normal. On day 4, the patient's peak temperature was 37·8°C, and his cough and dyspnoea had improved; intravenous azithromycin was stopped. On day 5, fever to a peak of 38·9°C occurred, and the patient developed rigors and severe coughing. Intravenous azithromycin (500 mg once a day) was restarted and oral clindamycin (300 mg once every 6 h) was administered, without clinical improvement. A repeat chest CT on day 6 showed enlargement of the right lower lobe opacity, which had become surrounded by a large new ground glass opacity. A new rounded opacity was present in the left lower lobe, and a new multilobulated opacity in the right upper lobe (figure 1C–E). The CT report suggested atypical pneumonia of fungal or viral origin. A repeat RT-PCR of an NP swab for SARS-CoV-2 was negative on day 7. Severe cough, malaise, rigors, and fever continued, and oxygen saturation was 92–94% at ambient air. Antibiotics were stopped on day 8, and prednisone 40 mg was given orally on the mornings of day 8 and day 9 for presumed cryptogenic organising pneumonia. Consulting radiologists noted CT evidence of a halo sign and reverse halo sign (figure 1B and 1E),7 suggestive of invasive fungal infection and not characteristic of previously reported CT findings for COVID-19.1, 8 On day 8, a serum galactomannan assay was ordered and pulmonary consultation was requested. The pulmonary consultant recommended bronchoscopy with transbronchial biopsy and BAL. Given the epidemic of COVID-19 in New York City at the time, the pulmonary team still considered COVID-19 a possible cause of the pulmonary disease.