Diagnosis

Diagnosing an aspergilloma or invasive aspergillosis can be difficult. Aspergillus is common in all environments but difficult to distinguish from certain other molds under the microscope. The symptoms of aspergillosis are also similar to those of other lung conditions such as tuberculosis.

Your doctor is likely to use one or more of the following tests to pinpoint the cause of your symptoms:

• Imaging test. A chest X-ray or computerized tomography (CT) scan — a type of X-ray that produces more-detailed images than conventional X-rays do — can usually reveal a fungal mass (aspergilloma), as well as characteristic signs of invasive aspergillosis and allergic bronchopulmonary aspergillosis.
• Respiratory secretion (sputum) test. In this test, a sample of your sputum is stained with a dye and checked for the presence of aspergillus filaments. The specimen is then placed in a culture that encourages the mold to grow to help confirm the diagnosis.
• Tissue and blood tests. Skin testing, as well as sputum and blood tests, may be helpful in confirming allergic bronchopulmonary aspergillosis. For the skin test, a small amount of aspergillus antigen is injected into the skin of your forearm. If your blood has antibodies to the mold, you'll develop a hard, red bump at the injection site. Blood tests look for high levels of certain antibodies, indicating an allergic response.
• Biopsy. In some cases, examining a sample of tissue from your lungs or sinuses under a microscope may be necessary to confirm a diagnosis of invasive aspergillosis.