Behind the (bilateral) fungus ball

Extract

A 54-year-old man with AIDS and a history of Pneumocystis jirovecii pneumonia presented with chronic cough and weight loss for 1 year. There was no haemoptysis. He had normal vital signs and was afebrile. Lung auscultation was normal. Laboratory evaluation was unremarkable. Chest radiography revealed bilateral upper lobe cavities with internal densities (figure 1). CT of the chest demonstrated these apical cavities to contain material consistent with a mycetoma (fungus ball). Adjacent pleural thickening and areas of consolidation and fibrosis were also present (figure 2). A CT scan performed 2 years previously showed normal lung parenchyma. Sputum fungal culture subsequently grew Aspergillus fumigatus. No antifungal therapy was administered, and the patient was eventually lost to follow-up.

Mould of the genus Aspergillus is ubiquitous in the environment and is a relatively common coloniser of the human airway. Its morphology is characterised by septate hyphae branching at acute angles. In the susceptible host, Aspergillus is associated with a gamut of lung involvement ranging from indolent to life-threatening. Invasive aspergillosis (IA) is a cause of acute angioinvasive pneumonia in the setting of profound immunosuppression. This infection requires urgent antifungal therapy. At the opposite end of the acuity spectrum is a simple aspergilloma (SA), which is a conglomerate of hyphal forms occupying a pre-existing lung cavity created by tuberculosis in most cases.¹ This condition is generally asymptomatic but can pose a danger if it leads to haemoptysis. Serum A. fumigatus IgG assays are usually positive, and about 50% of patients grow Aspergillus in respiratory cultures.² Chest CT shows an intracavitary mass, the mobility of which can be demonstrated by its dependent position on both supine and prone CT (figure 3). The unoccupied space within the cavity may assume the distinctive appearance of an air crescent also known as Monod’s sign (figure 4).³ Surgical resection is the preferred intervention in cases of haemoptysis with adequate lung function.