centrilobular

Centrilobular is an anatomical term used to describe the location at the center of a lobule. It is applied in histology and radiology to denote tissue regions around the central part of a lobule, such as the central vein in hepatic lobules or the center of the secondary pulmonary lobule in the lung. The terminology reflects a relative spatial relationship within a lobular unit rather than a defined structure.

In the liver, the classic hepatic lobule is described in zonal terms. The centrilobular zone, also called zone 3, surrounds the central vein and lies farthest from the portal triad. This region has a comparatively lower oxygen supply and is particularly vulnerable to ischemic or toxic injury. Centrilobular hepatocytes are commonly implicated in drug-induced liver injury, and histologic changes such as centrilobular necrosis can be seen in affected tissues.

In the lung, centrilobular (or centriacinar) describes pathology centered around the proximal parts of the respiratory bronchioles within a secondary pulmonary lobule. Centrilobular emphysema is the best-known example, typically associated with smoking and toxins, and it predominantly affects the central portions of the lobule with relative sparing of the peripheral alveolar tissue. Clinically, this pattern influences imaging findings and the distribution of air-space destruction, often with upper-lobe predominance.

Overall, centrilobular denotes a central localization within a lobule, with organ-specific patterns of vulnerability and disease that reflect the relative physiology and architecture of that region.