A<unk>  is a tuberculosis (TB) nodule that can form in the apex of the lung when a primary TB infection elsewhere in the body spreads to the lung apex via the bloodstream.<unk>  nodules are often calcified. The initial lesion is usually a small focus of consolidation, less than 2cm in diameter and located within 1 to 2 cm of the apical pleura. In adolescence,<unk>  foci may become reactivated and develop into Assmann foci. Such foci are sharply circumscribed, firm, gray-white to yellow areas that have a variable amount of central caseation and peripheral fibrosis.
Simon focus
Ghon focus
Rich focus
Hope in Hell 
Affective spectrum
Seeing is Believing 
Extensions to the International Phonetic Alphabet
Concept creep