Aneurysmal bone cyst of the parietal bone. Case report.

Aneurysmal bone cyst is a benign lesion of unknown pathogenesis seen more often in vertebrae and flat bones, and less commonly in the shaft of long bones. Skull involvement is rare and accounts for only 3-6% cases, generally in the first three decades of life. Histologically, the lesion is characterised by the presence of multiple localisations, filled with venous blood and lined by spindle-shaped fibroblasts with scattered multinucleated giant cells and stromal cells. An unusual case of aneurismal bone cyst of the parietal bone is reported.