Apical scarring of the lung, often referred to as apical caps, is found predominantly in older men and is usually a bilateral process present in individuals of lower socioeconomic class that increases with age. Such changes of apical scarring are not restricted to the upper lobes. It also can occur in the superior segments of the lower lobes. Studies performed in the early 1900s proposed tuberculosis as a root cause, but closer analysis of the available literature showed that granulomatous inflammation was seen only in a minority of cases. The combination of infection and chronic ischemia seems to be the likely etiology, with some authors favoring the latter. The appearance of fragmented fibers resembling elastosis seen at high power is suggestive of ischemia.