Monod sign
Monod sign simply describes air that surrounds a mycetoma (most commonly an aspergilloma) in a pre existing pulmonary cavity 1-3.
It should not be confused with the air crescent sign which is seen in recovering angioinvasive aspergillosis 4. The air crescent sign heralds improvement in the condition.
In practice it is likely that the term Monod sign will receive blank stares. The air around the mycetoma is often crescent shaped and hence, the term air crescent sign is used interchangeably by many to refer to both pathological processes.
