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The results suggest that the more aggressive biologic behavior of OKCs is related to the higher expression of MMP-9 and NF-κB in those lesions. The differences in the biologic behavior of the lesions studied do not seem to be associated with the angiogenic index.

Schwannomas, also known as neurilemmomas, are uncommon neoplasms apparently derived from Schwann cells. The growth of these tumors causes displacement and compression of the nerve of origin. Schwannomas are usually solitary lesions but can be multiple when associated with neurofibromatosis. Anti-S100 protein is the most widely used antibody for the identification of this neoplasm. Surgical excision is the treatment of choice for schwannomas, with few and controversial reports of recurrence or malignant transformation. The present article reports 7 additional cases of oral schwannoma, and the literature is reviewed regarding clinicopathologic features, immunohistochemical findings, differential diagnosis, and therapeutic management of this benign neural tumor. Crown

The increase in MC density associated with the strong expression of MMP-9 may favor SCC progression.

This study analysed the immunohistochemical expression of mast cell tryptase in giant cell fibromas (GCFs). In addition, the possible interaction of mast cells with stellate giant cells, as well as their role in fibrosis and tumour progression, was investigated. For this purpose, the results were compared with cases of inflammatory fibrous hyperplasia (IFH) and normal oral mucosa. Thirty cases of GCF, 30 cases of IFH and 10 normal mucosa specimens used as control were selected. Immunoreactivity of mast cells to the anti-tryptase antibody was analysed quantitatively in the lining epithelium and in connective tissue. In the epithelial component (p=0.250) and connective tissue (p=0.001), the largest mean number of mast cells was observed in IFHs and the smallest mean number in GCFs. In connective tissue, the mean percentage of degranulated mast cells was higher in GCFs than in IFHs and normal mucosa specimens (p<0.001). Analysis of the percentage of degranulated mast cells in areas of fibrosis and at the periphery of blood vessels also showed a larger mean number in GCFs compared to IFHs and normal mucosa specimens (p<0.001). The percent interaction between mast cells and stellate giant cells in GCFs was 59.62%. In conclusion, although mast cells were less numerous in GCFs, the cells exhibited a significant interaction with stellate giant cells present in these tumours. In addition, the results suggest the involvement of mast cells in the induction of fibrosis and modulation of endothelial cell function in GCFs.

Background and Purpose Chordomas notoriously demonstrate a paucity of changes following radiation therapy on conventional MRI. We hypothesize that dynamic contrast enhanced (DCE) MR perfusion imaging parameters of chordomas would change significantly following radiation therapy. Materials and Methods Eleven pathology-proven chordoma patients who completed DCE MR perfusion imaging pre -and post-radiation therapy were enrolled. Quantitative tumor measurements were taken by two attending neuroradiologists. ROIs were used to calculate vascular permeability (Ktrans) and plasma volume (Vp), and generate dynamic contrast enhancement curves. Quantitative analysis was performed to determine mean and maximum Vp and Ktrans values, while semi-quantitative analysis on averaged concentration curves was used to determine the area under the curve (AUC). A Mann-Whitney U test at a significance level of p<0.05 was used to assess differences of above parameters between pre- and post-radiation therapy. Results Vp mean (pre-treatment μ=0.82, post-treatment μ=0.42), Vp maximum (pre- treatment μ=3.56; post- treatment μ=2.27), and Ktrans mean (pre- treatment μ=0.046; post- treatment μ=0.028) in the ROIs significantly decreased after radiation therapy (p<0.05), thereby demonstrating potential for assessing tumor response. AUC values also demonstrated significant differnces (p<0.05). Conclusions Vp and Ktrans, decreased after radiation therapy, suggesting that these DCE-MR perfusion parameters may be useful for monitoring chordoma growth and response to radiation therapy. Additionally, the characteristic dynamic MR signal intensity time curve of chordoma may provide a radiographic means of distinguishing chordoma from other spinal lesions.

The larger number of MFBs suggests that these cells are one of the factors responsible for the more aggressive biological behavior of these lesions. The lack of correlation between the number of MFBs and immunoexpression of TGF-β1 and IFN-γ indicates that these proteins are not involved in the differentiation of this type of contractile cell in the lesions studied and that only the use of immunohistochemistry to establish such a correlation is a limiting factor.

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