Presentation
History withheld.
Patient Data
PA chest x-ray demonstrates a rounded density in the right midzone with an air crescent.
CT of the chest demonstrates a nodule with peripheral ground glass opacity. The central component is retracting away from the rest of the region with the formation of an air crescent.
Case Discussion
This patient is neutropaenic but has improving cell counts. The development of an air crescent sign in the setting of angioinvasive aspergillosis is a good prognostic sign, denoting separation of the infarcted core from host response / granulation tissue.
This should not be confused with an aspergilloma which occurs in patients with normal immunity and represents colonization by aspergillus of a previously existing cavity (most commonly TB).