Final answer:
A fungal ball, or an aspergilloma, commonly develops within lung cavities previously damaged by disease in conditions such as aspergillosis.
Step-by-step explanation:
Formation of Fungus Balls in Preexisting Cavities
The formation of a fungus ball within preexisting cavities is a common development in certain mycoses, particularly in the lungs.
A fungus ball, also known as an aspergilloma, is a mass of fungal hyphae that typically forms in lung cavities previously damaged by issues such as tuberculosis, sarcoidosis, or lung abscesses.
Aspergillosis, caused by the filamentous fungus Aspergillus, is a notable condition in which patients, especially those who are immunocompromised, may develop these fungal balls.
Patients with weakened immune systems, such as those in the late stages of AIDS or those undergoing chemotherapy, are at a greater risk of developing aspergillosis.
In systemic mycoses like histoplasmosis or coccidioidomycosis, which spread to internal organs and mainly enter the body through the respiratory system, the formation of granulomatous lesions can lead to cavities where fungal balls might develop.
Treatment of these mycoses often requires potent antifungal medications, which can have serious side effects.
Note, opportunistic mycoses such as Pneumocystis pneumonia (PCP) caused by Pneumocystis jirovecii can also affect the lungs of immunocompromised patients, although they don't form a typical fungus ball like aspergillosis does.