Sacculation

Sacculation is a biological and anatomical term used to describe the formation or enlargement of sac-like structures, or saccules, within tissues or organs. It denotes morphological changes that create hollow, sac-shaped cavities and can involve either outward protrusions (evaginations) or inward folding (invaginations) of epithelial or other cellular layers. The word derives from Latin sacculus, meaning a small bag.

In development, sacculation refers to morphogenetic events during organogenesis in which sac-shaped compartments arise from existing tissues, such as epithelial or endothelial structures. In mature tissues, sacculation may occur as a response to mechanical, chemical, or inflammatory stimuli, producing saclike dilations or outgrowths. The usage of the term varies by field; it is often a descriptive descriptor rather than a standardized diagnosis.

Clinical and pathological contexts sometimes employ related phrases such as saccular dilation or saccular aneurysm, referring to sac-like enlargements in blood vessels, or saccular bronchiectasis, a form of bronchiectasis characterized by sac-like dilations of the airways. However, sacculation itself is not a single, universally defined condition, and more precise terminology is typically preferred in radiology, pathology, and anatomy.

See also: sac, sacculus, saccule, saccular aneurysm, bronchiectasis, diverticulum.