Ghon focus



A Ghon focus is a primary lesion caused by mycobacterium bacilli (tuberculosis) developed in the lung of a previously uninfected individual. It is named for Anton Ghon (1866-1936), a Czech pathologist.

It is a small area of granulomatous inflammation, only detectable by chest X-ray if it calcifies or grows substantially (see tuberculosis radiology). Typically these will heal, but in some cases, especially in immunosuppressed patients, it will progress to miliary tuberculosis (so named due to the calcified granulomas resembling millet seeds on a chest X-ray).

The classical location for primary infection is surrounding the lobar fissures, either in the upper part of the lower lobe or lower part of the upper lobe.

If the Ghon focus also involves infection of surrounding lymph nodes, it is known as the Ghon Complex.