Jun Takasu

Aneurysmal bone cyst of the mandible

Aneurysmal bone cyst is a multilocular cystlike lesion in the bone which is filled with blood. In 1942, Jaffe and Lichtenstein1 separated a cystic lesion containing numerous pools of blood from other cysts, and in 1950 Lichtenstein2 proposed the name “aneurysmal bone cyst” for this entity. He stated that the aneurysmal bone cyst usually occurred in vertebrae, clavicle, rib, and limb bones and produced eccentric bone expansion with numerous pools of blood. The histologic findings showed that spongy bone and marrow were replaced by a fibrous tissue in which hemorrhage, giant cell reaction, and reparative new bone formation were observed. Lichtenstein3 reported statistically that vertebrae and limb bones were commonly affected, constituting about 60% of the total number of cases. Studies by Biesecker et al4 and Ruiter et al5 showed almost the same result. The aneurysmal bone cyst rarely affects the craniofacial bones. Biesecker reported only two cases in the mandible in 66 cases, and Ruiter reported one case in the maxilla in 105 cases. Daugherty6 mentioned that only 2% of these lesions were in the facial bones.

Ultrastructural localization of alkaline phosphatase in the calcifying epithelial odontogenic tumor

The localization of alkaline phosphatase in a calcifying epithelial odontogenic tumor obtained from a 53-year-old man was examined cytochemically. The majority of enzyme activity was associated with the epithelial cell membranes of the tumor, and faint activity was found in the cell membranes facing the adjacent stromal tissue. The reaction product of ALP was also detected in some membrane-bound vacuoles (lysosomes) and the Golgi apparatus of tumor cells. It is suggested that the appearance of enzyme activity associated mostly with the epithelial cell membrane may be related to transport function of cell membranes.