Aspergillus nodules; another presentation of Chronic Pulmonary Aspergillosis
September 30 2016
Key findings: Cough alone was a common presenting symptom, significant proportion of these patients does not have a detectable Aspergillus IgG and it’s difficult to distinguish Aspergillus nodules from other pathology on CT findings alone.
Thirty three patients with Aspergillus nodules have been described with radiology and histology findings combined with clinical features and laboratory parameters; in particular Aspergillus IgG has been published by Eavan Muldoon and colleagues. Lung nodules caused by Aspergillus spp have been peripherally mentioned by other authors, but not well described. They present as single or multiple nodule(s) usually without cavitation in immune competent hosts.
Positron emission tomography (PET) scan of a patient with chronic pulmonary aspergillosis showing a 2 cm cavitating mass in the right upper lobe with high fluorodeoxyglucose (FDG) uptake plus an area of fibrosis surrounding the mass extending to the pleura with intermediate FDG uptake. (Source: Caroline G Baxter et al. Thorax 2011; 66:638-640)
This study was conducted at the National Aspergillosis Centre (NAC), Manchester, UK. Patients were identified by one of two methods. First, patients with pulmonary nodules on chest imaging at presentation, and features consistent with a diagnosis of aspergillosis (i.e. biopsy proven disease and/or positive Aspergillus serology and/or Aspergillus spp isolated form respiratory secretions) were prospectively recorded. Second, additional case finding was performed by the retrospective review of patient correspondence and review of histopathology records.
Ten patients had proven disease, and the remainder deemed probable disease, based on serology and culture results. Twenty nine patients (88%) reported cough, 23 (70%) dyspnoea, 11 (33%) described weight loss, and 5 (15%) haemoptysis. No patients reported a history of fever. Ten patients (31%) did not have an elevated Aspergillus IgG, and only 4 patients had elevated Aspergillus precipitins. Twelve patients (36%) had a single nodule, six patients (18%) had between 2 and 5 nodules, 2 (6%) between 6 and 10 nodules and 13 (39%) had more than 10 nodules. The mean size of the nodules was 21 mm, with a maximum size ranging between 5–50 mm. Eleven patients had emphysema visible on CT scanning.
In this series, cough alone was a common presenting symptom. A significant proportion of these patients do not have a detectable Aspergillus IgG, meaning biopsy is necessary to exclude malignant disease, especially as many have positive PET scans. CPA should be a differential diagnosis in patients presenting with single or multiple pulmonary nodules. The authors proposed a management algorithm.