The reverse halo sign and spontaneous pneumothorax due to pulmonary mucormycosis.

Pulmonary mucormycosis (PM) is a rare opportunistic fungal infection that commonly affects immunocompromised patients. Early diagnosis and initiation of appropriate anti-fungal therapy are crucial, as delay in diagnosis leads to increased mortality. However, the diagnosis is often challenging because of the lack of utility of serum markers and low culture sensitivity. Definitive diagnosis often requires invasive tissue sampling, which may delay treatment. Therefore, chest imaging findings play an important role in the diagnosis of suspected cases. This case highlights the importance of classic reverse halo sign and presence of necrotizing cystic changes resulting in spontaneous pneumothorax in a patient who was later found to have invasive PM.