Abstract
For the purpose of clarifying the growth and infiltration into the mandibular bone by carcinoma cells, VX2 carcinoma cells were transplanted into the masseter of domestic rabbits and its mode of invasion was investigated with the light microscopy and the scanning electron microscopy (SEM) as well as the electron probe X-ray microanalyser (EPMA).
The results were as follows;
1. Light microscopic examination demonstrated that VX2 carcinoma cells formed substantial cellular foci localized to the masseter in the 1st week after transplantation, then destroyed the periosteum in the 2nd week, and infiltrated and proliferated within the mandibular bone in the 3rd and 4th weeks.
2. When the bone surface adjacent to the tumor was examined with SEM, a large number of resorption lacunae being irregular in shape were found in the VX2 carcinoma cell-infiltrating site of the mandibular bone. Small bone cavities were found at the bottom of resorption lacunae. Collagen fibers were running in various directions depending on the depth, some of them formed net-like patterns while others were fragmented.
3. X-ray microanalysis of the VX2 carcinoma cell-infiltrating site using EPMA demonstrated some decrease of Ca in the region adjacent to the tumor prior to infiltration of VX2 carcinoma cells into the mandibular bone. As the infiltration of VX2 carcinoma cells into the mandibular bone progressed, the peak level of Ca decreased significantly whereas almost no change was observed in the peak of P.
These results indicate that three dimentional examination of carcinoma-infiltrating site in the jaw bone using SEM combined with investigation of Ca distribution with EPMA might be a useful clinically and applicable tool in defining the margin of carcinoma infiltration into the jaw bone.
