pacchionian granulations

a·rach·noid gran·u·la·tions

[TA]
tufted prolongations of pia-arachnoid, composed of numerous arachnoid villi that penetrate dural venous sinuses and effect transfer of cerebrospinal fluid to the venous system. In older people, these are more numerous and tend to calcify.

pacchionian granulations

Pacchioni,

Antonio, Italian anatomist, 1665-1726.
pacchionian bodies - tufted prolongations of pia-arachnoid. Synonym(s): arachnoid granulations; pacchionian corpuscles; pacchionian glands; pacchionian granulations
pacchionian corpuscles - Synonym(s): pacchionian bodies
pacchionian depressions - pits on the inner surface of the skull in which are lodged the arachnoidal granulations. Synonym(s): granular pits
pacchionian glands - Synonym(s): pacchionian bodies
pacchionian granulations - Synonym(s): pacchionian bodies

pacchionian granulations

enlargements of the arachnoid villi which protrude into the dorsal sagittal sinus, as seen in the horse.
References in periodicals archive ?
Pacchionian granulations are hypertrophic arachnoidal villi, which can erode through cranial bone, causing lytic lesions on skull roentgenograms or computed tomography (CT) scans.
If hypertrophic, such arachnoid villi are then called pacchionian granulations, which can erode even further, reaching the outer table of the cranium and causing a punched-out lesion on roentgenograms.
Pacchionian granulations are reported more frequently among adults, but earlier stages of hypertrophic arachnoid villi can be present as early as 18 months of age.
Because of the osteolytic appearance of pacchionian granulations on roentgenograms, the differential diagnosis includes all other osteolytic lesions of the calvarial bone, including dermoid/epidermoid cyst, osteoma, enchondroma, fibroma, fibrous dysplasia, and calvarial hemangioma.
Pacchionian granulations are benign overgrowth of arachnoidal villi that have a radiolucent appearance on a skull X-ray.