What is seen in the healed stage of primary tuberculosis?

In the healed stage of primary tuberculosis, the Ghon complex is commonly observed as a characteristic finding. The Ghon complex consists of a calcified primary focus of infection, typically in the lung, along with involvement of the regional lymph nodes that have also undergone calcification. This complex represents an immune response to the primary infection with Mycobacterium tuberculosis, indicating that the initial infection has been contained and is in a state of quiescence.

As the body mounts an immune response, inflammation occurs at the site of infection, leading to a granulomatous reaction that can heal, resulting in calcification. The presence of the Ghon complex indicates that the individual has been exposed to the tuberculosis bacterium and has effectively responded to control the infection, even if the person remains at risk for reactivation later.

Nodular lesions and cavitary lesions tend to be associated with active disease or reactivation of tuberculosis rather than the healed stage. Pleural effusion might occur in a variety of conditions, including active tuberculosis, but is not a hallmark feature of healed primary tuberculosis.