Aspergilloma (mycetoma, fungus ball) is an intracavitary fungal mass formed by colonization of Aspergillus species (usually A. fumigatus) within a pre-existing pulmonary cavity or cystic space. It most commonly develops in cavities resulting from tuberculosis, sarcoidosis, or bronchiectasis. The air-crescent sign is pathognomonic. It is clinically significant due to the risk of life-threatening hemoptysis.
Age Range
40-70
Peak Age
55
Gender
Male predominant
Prevalence
Uncommon
Aspergilloma develops when inhaled Aspergillus spores colonize a pre-existing pulmonary cavity (most commonly a TB cavity). Fungal hyphae, mucus, inflammatory debris, and fibrin combine to form an intracavitary mass (fungus ball). This mass is not adherent to the cavity wall — it shifts with gravity (Monod sign). Bronchial arteries in the cavity wall undergo hypertrophy, and vascular invasion by fungal hyphae leads to hemoptysis. The air-crescent sign reflects the air crescent between the fungus ball and the cavity wall — this space indicates the fungus ball does not completely fill the cavity. Cavity wall thickening and pleural reaction develop over time.
Crescent-shaped air space between the cavity wall and the intracavitary fungus ball. Pathognomonic for aspergilloma, indicating the fungus ball does not completely fill the cavity. Best evaluated on lung window. The location of the air crescent changes with positional change (together with Monod sign).
A round or oval intracavitary mass of soft tissue attenuation within a pre-existing cavity, with a crescent-shaped air space between the mass and the cavity wall (air-crescent sign). The mass partially fills the cavity lumen and is typically located in the dependent position.
Report Sentence
An intracavitary mass of soft tissue attenuation is noted within a __ mm cavity in the right/left upper lobe with a crescent-shaped air space between the mass and cavity wall (air-crescent sign); findings are consistent with aspergilloma.
The intracavitary mass shifts with gravity on CT scans obtained in prone and supine positions (Monod sign). This finding proves the mass is not adherent to the cavity wall and is free-floating.
Report Sentence
The intracavitary mass is noted to shift with positional change (Monod sign); free-floating mass within the cavity supports the diagnosis of aspergilloma.
Cavity wall thickening and adjacent pleural thickening/reaction. These findings reflect the chronic inflammatory process and the effect of fungal colonization on the cavity wall.
Report Sentence
Cavity wall thickening and adjacent pleural reaction are noted, consistent with chronic aspergilloma; clinical follow-up is recommended regarding hemoptysis risk.
Hypertrophied bronchial arteries may be seen in the cavity wall on contrast-enhanced CT. These findings indicate the source of hemoptysis and are important for embolization planning.
Report Sentence
Hypertrophied bronchial arteries are noted in the cavity wall on contrast-enhanced CT and are considered the source of hemoptysis; bronchial artery embolization may be planned.
The fungus ball shows low signal intensity on T2-weighted MRI. This finding results from the low water content and dense hyphal structure of the fungus ball. Inflammation and fluid surrounding the cavity are hyperintense on T2.
Report Sentence
A low-signal intracavitary mass is noted within the cavity on T2-weighted sequences, consistent with fungus ball (aspergilloma).
Sponge-like internal air pockets may be seen within the fungus ball. These findings reflect air bubbles trapped between hyphae and help distinguish the intracavitary mass from a solid tumor.
Report Sentence
Sponge-like internal air pockets are noted within the intracavitary mass, consistent with fungus ball structure.
Criteria
Single fungus ball in a single cavity, thin-walled cavity (<3 mm), minimal disease in surrounding parenchyma, normal pulmonary function
Distinct Features
Best candidate for surgical resection. Lobectomy or segmentectomy can be performed with low mortality rate. Usually presents as asymptomatic or with mild hemoptysis.
Criteria
Multiple cavities or multiple fungus balls in a single cavity, thick-walled cavity, extensive disease in surrounding parenchyma (fibrosis, bronchiectasis), impaired pulmonary function
Distinct Features
Surgical risk is high. Bronchial artery embolization is preferred for hemoptysis control. Risk of progression to chronic pulmonary aspergillosis exists. Cavernostomy or intracavitary antifungal treatment may be considered.
Criteria
In addition to aspergilloma, progression in cavity number/size, pleural thickening, consolidation, symptoms >3 months, Aspergillus IgG positive
Distinct Features
Shows subacute/chronic course and progresses without treatment. Long-term antifungal therapy (itraconazole/voriconazole) is required. Can develop even in absence of immunosuppression — usually underlying structural lung disease (COPD, sarcoidosis, prior TB) is present.
Distinguishing Feature
Lung abscess shows air-fluid level within a thick smooth-walled cavity but no free intracavitary solid mass. Aspergilloma has an intracavitary solid mass (fungus ball) and air-crescent sign. Abscess wall enhances, aspergilloma cavity wall may be thinner.
Distinguishing Feature
Cavitary squamous cell carcinoma shows irregular thick-walled cavity with nodular component in the cavity wall. The mass is invasive to the cavity wall and not free — does not move with positional change. In aspergilloma, the fungus ball is free and Monod sign is positive.
Distinguishing Feature
Tuberculoma is a solid nodule that may develop internal cavitation but free intracavitary mass and air-crescent sign are not expected. Central/laminated calcification and satellite nodules are typical for tuberculoma. In aspergilloma, a free mass within a pre-existing cavity is present.
Distinguishing Feature
Pulmonary embolism-infarct can progress to cavitation but free intracavitary mass is not expected. Hampton hump (wedge-shaped peripheral opacity) is typical. Air-crescent sign is specific to aspergilloma.
Urgency
urgentManagement
surgicalBiopsy
Not NeededFollow-up
3-monthAspergilloma may require emergency intervention due to risk of massive hemoptysis (>300 mL/24 hours). Bronchial artery embolization is the first intervention in hemoptysis. Definitive treatment is surgical resection (lobectomy in simple aspergilloma). In complex aspergilloma, surgical risk is high — antifungal therapy and embolization are preferred. CT follow-up at 3-6 month intervals is performed in asymptomatic patients. Galactomannan antigen and Aspergillus IgG serology support the diagnosis. Risk of progression to invasive pulmonary aspergillosis should be evaluated in immunosuppressed patients.
Asymptomatic aspergillomas can be followed. Surgical resection or bronchial artery embolization is needed when hemoptysis is present. Antifungal therapy (itraconazole, voriconazole) can be given as adjunct.