Clinical and histopathological studies on the characteristics of growth of mandibular ameloblastoma
1991 Volume 37 Issue 9 Pages 1600-1615
Details
1991 Volume 37 Issue 9 Pages 1600-1615
The growth characteristics of primary ameloblastoma were examined in 30 resected mandibles. In all cases, whole tissue sections were prepared and microscopic examinations were conducted on 122 marginal regions of the tumors. Statistical analyses were employed to determine the factors which are related to the growth characteristics.
1. The growth characteristics of the tumor were histologically classified into two major patterns: expansive and invasive. Based on the parenchymal morphology of the margin, the former was further divided into flat and saw-tooth types, and the latter into cord-like, sporadic, and diffuse types. Most ameloblastomas examined displayed multiple types of growth simultaneously.
2. The outer layer cells of the tumors were classified into 3 types: cuboidal, columnar, and basal cells. The cuboidal cell type had a tendency of being expansive, the basal cell type was apt to be invasive, and the columnar cell type showed both characteristics.
3. The relationship between the host site and the growth patterns has revealed that the tumors in the alveolar region invaded the cancellous bone, while the tumors in other regions had a tendency of being expansive, especially in the mandibular ramus. This finding suggests that differences in the inner architecture of the mandible can affect the tumor growth.
4. In order to predict the growth pattern of the tumor prior to surgery, the quantification theory Type II of Hayashi was employed with the following parameters: 1) the histological type of the outer layer cells, 2) the host site, 3) radiographical features, and 4) macroscopic appearances i.e. cystic or solid. Then the result was evaluated in comparison with the histological figures of the marginal regions of the tumors. It was found that the estimation was as accurate as 78.7%.
We concluded treatment should be carried out after careful consideration of the growth pattern at various anatomical sites of the mandible.
