Aspergillus in the lung: diverse and coincident forms

Abstract

Pulmonary disease caused by the fungus Aspergillus has traditionally been regarded as belonging to one of the following, apparently distinct, entities: saprophytic aspergilloma; allergic bronchopulmonary aspergillosis (ABPA); and invasive aspergillosis (IPA); which may be further categorised as angioinvasive, acute or chronic airway invasive) [1]. It is not always obvious that there is overlap between these entities, and that in any given patient more than one Aspergillus-related pathological process can co-exist [2]. The aim of this article is to review the clinical and imaging features of the main categories of Aspergillus-related pulmonary disease and, in particular, to highlight the overlap between them.

Nontuberculous mycobacterial disease and Aspergillus-related lung disease in bronchiectasis

“…Since the radiological features of ABPA, including central bronchiectasis and pulmonary infiltrates, are difficult to differentiate in patients with bronchiectasis and NTM infection, clinical and serological criteria, including episodic bronchial obstruction (asthma), peripheral blood eosinophilia and positive Aspergillus serology, were used to diagnose ABPA [18]. HRCT scans were evaluated for features of CNPA: multiple nodules, focal consolidation, tree-in-bud appearance and mycetoma formation [7].…”

“…Pulmonary disease caused by A. fumigatus is traditionally classified into three distinct groups, namely aspergilloma, ABPA and invasive aspergillosis. There may be a clinical and radiological overlap between these groups as more than one Aspergillus-related lung disease can coexist [7]. Invasive aspergillosis has been further categorised as angio-invasive and acute or chronic airway invasive aspergillosis (chronic necrotising pulmonary aspergillosis (CNPA) or semi-invasive aspergillosis) [7,8].…”

“…There may be a clinical and radiological overlap between these groups as more than one Aspergillus-related lung disease can coexist [7]. Invasive aspergillosis has been further categorised as angio-invasive and acute or chronic airway invasive aspergillosis (chronic necrotising pulmonary aspergillosis (CNPA) or semi-invasive aspergillosis) [7,8]. The former is an aggressive form of aspergillosis seen in severe immunosuppression, whereas the latter is an indolent form of invasive aspergillosis, which has been associated with NTM infection [9].…”

High-resolution CT of complications of idiopathic fibrotic lung disease

“…Patients with IPF are at risk of developing aspergillomas (resulting from saprophytic colonisation of a pre-existing lung cavity) and chronic airway invasive aspergillosis (an indolent form of cavitatory Aspergillus infection, also termed chronic necrotising or semi-invasive aspergillosis). It is now recognised that there is overlap between these clinicopathological entities [24] and therefore the simpler term ''aspergillosis'' may be more appropriate when the distinction of simple mycetoma from chronic airway invasive aspergillosis is not obvious.…”

“…Although aspergilloma most frequently develops in a cavity resulting from advanced fibrotic sarcoidosis or from previous TB, the condition has been described in a range of other fibrocavitary disease, including IPF [17,24,25]. Surrounding fibrotic scarring and preexisting lung disease impair detection of aspergillomas on chest radiograph and CT is more sensitive than chest radiography, detecting both early changes and smaller lesions [17,25].…”