The lesion produced in the lung of a previously uninfected person by tubercle bacilli. It is a small focus of granulomatous inflammation, which may become visible on a chest X-ray if it grows large enough or if it calcifies. A Ghon focus usually heals without further trouble, but in some patients tuberculosis spreads from it via the lymphatics, the air spaces, or the bloodstream. A. Ghon (1866–1936), Czech pathologist
Subjects: Medicine and Health.