Cementum-like material in a case of Pindborg tumor.

Pindborg tumor is characterized by the production of large amounts of amyloid and the presence of calcified lamellar bodies. These bodies were investigated at both the light and ultrastructural levels in a case of Pindborg tumor showing extensive calcification. It was found that the great majority represented calcified amyloid. However the outer layer or layers in some of these bodies consisted of typically banded calcified collagen which was referred to in this paper as (cementum-like material). This term was preferred over (bone-like material) because of the striking similarity between the arrangement of collagen in this layer and that of cemental Sharpy's fibers. It is therefore suggested that although the majority of the calcified lamellar bodies in this tumor represents calcified amyloid, cementum-like material may also contribute a part.