Aspergillus nodules are a form of chronic pulmonary aspergillosis (CPA) where small rounded lesions develop in the lungs due to infection with Aspergillus fungi. These nodules are usually discovered during CT scans performed for investigation of symptoms or to rule out lung cancer.
Many Aspergillus nodules remain stable for long periods and may not require treatment, but they usually need long-term monitoring to ensure they do not grow or develop into other forms of aspergillosis.
Key points
- Aspergillus nodules are a form of chronic pulmonary aspergillosis.
- They appear as small rounded lesions in the lungs on CT scans.
- Symptoms may be mild or absent.
- Diagnosis can be difficult and sometimes requires lung biopsy.
- Many nodules remain stable and may not need treatment.
- Regular monitoring with scans is usually recommended.
Table of contents
Overview
Lung nodules are small dense spots seen on chest imaging such as an X-ray or CT scan. Many lung nodules are harmless, but some can be caused by infections, inflammation, autoimmune disease, or cancer.
Aspergillus nodules are nodules caused by infection with Aspergillus fungi. They represent a localised form of fungal infection in the lung and are considered part of the spectrum of chronic pulmonary aspergillosis (CPA).
Because nodules can resemble lung cancer on scans, they are often discovered during investigations for suspected cancer. Being told that a lung nodule may be cancerous can be extremely frightening, and many patients only discover later that the cause is a fungal infection.
Some Aspergillus nodules remain stable for years and cause no problems. Others may slowly enlarge, form cavities, or develop into other forms of chronic pulmonary aspergillosis.
Symptoms
Symptoms of Aspergillus nodules can be mild or absent. In fact, many nodules are discovered incidentally during scans performed for unrelated reasons.
When symptoms do occur, they can overlap with other lung conditions such as chronic pulmonary aspergillosis (CPA), chronic obstructive pulmonary disease (COPD), or bronchiectasis.
Possible symptoms include:
- Persistent cough
- Shortness of breath
- Fatigue
- Weight loss
- Fever
- Coughing up blood (haemoptysis)
However, many people with Aspergillus nodules have no symptoms at all.
Causes
Aspergillus nodules form when the body reacts to inhaled fungal spores. Instead of spreading widely, the infection becomes contained within a small area of lung tissue.
The body may surround the fungus with granulation tissue and inflammatory cells, forming a small localised lesion (nodule).
Nodules can develop in several situations:
- As part of chronic pulmonary aspergillosis (CPA)
- In people with mild immune dysfunction
- In patients with underlying lung disease
- Occasionally in otherwise healthy individuals
Unlike invasive aspergillosis, Aspergillus nodules usually occur in people whose immune systems are largely functioning.
Diagnosis
Aspergillus nodules are often first seen on a CT scan of the chest.
Because they can resemble lung cancer or tuberculosis, doctors often need to perform additional tests.
Blood tests
Blood tests may include:
- Aspergillus IgG antibodies
- Precipitins
However, these tests may sometimes be negative even when nodules are caused by Aspergillus.
Sputum testing
Sputum samples may be examined for fungal culture or PCR testing, but these are often negative in patients with isolated nodules.
Biopsy
In some cases a needle biopsy or surgical removal of the nodule is required to confirm the diagnosis. Tissue samples can be examined under the microscope for fungal structures typical of Aspergillus.
This approach is more invasive but may be necessary when cancer cannot be ruled out.
Treatment
Not all Aspergillus nodules require treatment.
In many cases doctors recommend a watch-and-wait approach with periodic CT scans. This helps avoid unnecessary exposure to antifungal medicines, which can have significant side effects.
Treatment may be recommended if:
- The nodule grows
- New nodules appear
- Symptoms worsen
- Other forms of aspergillosis develop
Antifungal treatment may include medications such as:
- Voriconazole
- Itraconazole
- Isavuconazole
In some patients with a single nodule, surgical removal may be recommended. Antifungal treatment is sometimes given afterwards to reduce the risk of recurrence.
Prognosis
The long-term behaviour of Aspergillus nodules can be difficult to predict.
Many nodules remain stable for years and never cause significant problems.
However, possible outcomes include:
- Remaining stable
- Shrinking over time
- Growing slowly
- Developing into a cavity containing fungal debris (an aspergilloma)
- Progression to other forms of chronic pulmonary aspergillosis
Because of this uncertainty, regular follow-up imaging is usually recommended.
Further information
Aspergillus nodules are relatively uncommon and remain an under-studied form of aspergillosis. Reliable patient information can therefore be difficult to find.
The National Aspergillosis Centre has published research on Aspergillus nodules seen in patients attending the clinic:
Muldoon EG, Sharman A, Page I, Bishop P, Denning DW. Aspergillus nodules; another presentation of Chronic Pulmonary Aspergillosis. BMC Pulm Med. 2016 Aug 18;16(1):123. doi: 10.1186/s12890-016-0276-3. PMID: 27538521; PMCID: PMC4991006.
This paper may be useful for patients who want to learn more or share information with their doctors.
Last reviewed: March 2026
Source: National Aspergillosis Centre patient information