To our surprise, none of the lung biopsies showed any presence of invasive aspergillosis. Lack of evidence for invasive pulmonary aspergillosis in our patients with probable CAPA raises the question whether patients with suspected CAPA truly develop invasive aspergillosis and require antifungal therapy. For instance, the three deaths in the CAPA report from France were attributed to bacterial septic shock, and not to aspergillosis. Although in our patients adequate antifungal treatment could be an explanation for the absence of histologic fungal features, we find this improbable as respiratory conditions deteriorated despite treatment. Further research on the presence of CAPA, its case definition and the necessity for antifungal treatment and (relative) contraindication for steroid treatment is needed.