Pathogenesis and clinical features of chronic pulmonary aspergillosis - is it possible to distinguish CNPA and CCPA clinically?

Background: The pathogenesis of chronic pulmonary aspergillosis (CPA) including chronic necrotizing pulmonary aspergillosis (CNPA), chronic cavitary pulmonary aspergillosis (CCPA), and simple aspergilloma (SA) has been poorly investigated. We examined all types of CPA cases with histopathological evidence to clarify the differences in pathogenesis and clinical features.

Method: We searched for cases diagnosed as pulmonary aspergillosis by histopathological examination in Nagasaki University Hospital between 1964 and September 2010. All available clinical information including radiological findings were collected and analyzed.

Result: We found 7, 5, 8, and 7 cases of proven CNPA, probable CNPA, CCPA, and SA, respectively. The radiograph of proven and probable CNPA was initially infiltrates or nodules that progress to form cavities with or without aspergilloma, whereas the radiograph of CCPA showed pre-existed cavities and peri-cavitary infiltrates with or without aspergilloma. The patients with proven and probable CNPA exhibited not only respiratory symptoms but also systemic symptoms and malnutrition. Aspergillus fumigatus was the most frequently isolated Aspergillus species (n = 14), however, Aspergillus niger was the predominant isolated species in proven CNPA cases (n = 4).

Conclusion: Our data indicate that the cases with chronic infiltration, progressive cavitation, and subsequent aspergilloma formation should be diagnosed as CNPA, and the cases with pre-existed cavities showing peri-cavitary infiltrates with or without aspergilloma would mean CCPA. However, it may be difficult to distinguish the two subtypes if a series of adequate radiography films are not available. We propose the term "chronic progressive pulmonary aspergillosis (CPPA)" for the clinical syndrome including both CNPA and CCPA.