Which condition involves cavity formation and is often found in the upper lobes?

The condition that involves cavity formation and is often found in the upper lobes is tuberculosis. Tuberculosis (TB) is a bacterial infection caused by Mycobacterium tuberculosis, which commonly affects the lungs. One of its hallmark features, especially in reactivation TB, is the development of cavitary lesions in the upper lobes of the lungs. These cavities occur as the tissue becomes necrotic and is often visible on chest radiographs or CT scans.

In the context of tuberculosis, the cavities form due to the body's immune response and the destruction of lung tissue. This is in contrast to other lung conditions. For instance, pneumonia typically involves consolidation rather than cavitation and can occur in various lobes, not specifically the upper lobes. A pulmonary embolus relates to blockage of blood vessels in the lungs and does not involve cavitary lesions. Atelectasis refers to the collapse of lung sections and does not imply the formation of cavities. Thus, tuberculosis is the condition most directly associated with cavity formation in the upper lobes.