Clinical Oral Pathology

Objective. The aim of this study was to describe the clinicopathologic and immunohistochemical characteristics of 14 cases of central odontogenic fibroma (COF), and the ultrastructural features of 2 of them. Study design. Collaborative retrospective study based on the records of 4 oral pathology diagnostic services in Latin America based on the current World Health Organization classification. Results. There were 7 male and 7 female patients (mean age 31.8 years). Eight tumors occurred in the maxilla and 6 in the mandible. Thirteen cases were epithelium-rich and 1 epithelium-poor COF. Three were classified as hybrid COF with giant cell lesion. Mean size of the hybrid lesions were larger than pure COF (3.8 vs. 2.4 cm). Odontogenic epithelial islands were immunoreactive for cytokeratin (CK) AE1/AE3, CK5, CK14, CK19, and 34BE12 and negative for CK1 and CK18. Langerhans cells positive for S-100 and CD1a were found within the epithelial islands in 6/6 tested cases. CD68 was expressed in the giant cells of the hybrid lesions and in a few mononuclear cells of 2 cases of COF. Ki-67 index was Ͻ1% in all cases. In 6 tumors (42.8%), there were small globular eosinophilic droplets within the epithelial islands, which were positive for collagen type IV, and 9/13 cases (69.2%) were focally positive for smooth muscle actin. In addition to fibroblasts, myofibroblastic differentiation was found in the 2 cases studied ultrastructurally. Conclusions. Immunohistochemistry was useful to confirm the presence of epithelium and to exclude other central fibrous tumors. COF also contains a variable number of mast cells, Langerhans cells, and myofibroblasts, and further studies are needed to better understand the participation of these cells in COF histogenesis.

History. In 1922, Ewing1 described a rare and some-what obscure intravascular endothelioma in the cor-pus cavernosum. He also described some cases of encapsulated, slow growing subcutaneous tumors with abundant endothelial cells occurring in dilated varicose veins with previously ...

Reports about the frequency of odontogenic tumors are scarce, and diagnostic criteria used in the reports are not uniform. This article presents the results of a retrospective study of odontogenic tumors recorded in four services of diagnostic pathology in Mexico City (two dental schools, one cancer hospital, and one private oral pathology service). The final diagnosis in each case was based on tbe 1992 histologic criteria of the World Health Organization. The frequency of odontogenic tumors, expressed as a percent of all oral and maxillofacial specimens, ranged from 0.8% in the cancer hospital (0.02% of all biopsies) to 3.7% in the private oral pathology service. The frequency was identical for the two dental school s (2.5%). We found a total of 349 odontogenic tumors; of these, 345 were benign (98.8%), and 4 (1.1%) were malignant (3 were primary intraosseous carcinomas and 1 was a malignant ameloblastoma). The most frequently occurring tumors were odontoma (34.6%), ameloblastoma (23.7%), myxoma (17.7%), adenomatoid odontogenic tumor (7.1%), and calcifying odontogenic cyst (6.8%). Although relatively rare, odontogenic tumors are still an important cause of extensive surgical procedures in

Background: Despite the improvements of treatment, oral cancer still has a high mortality rate. Mutations in p53 tumor suppressor gene has been suggested to play a significant role in the development of various epithelial carcinomas and their response to therapy. Aim: To investigate the incidence p53 mutations in patients with OSCC (Oral Squamous Cell Carcinoma), and to find possible correlation of p53 core domain mutations (exon 4 8) with patients clinical course of disease. Patients and Methods: We analysed 42 patients with stage II and III of histologically confirmed OSCC of the tonguae or oral floor (G1, G2 and G3). More than 93% of patients were heavy smokers and alcochol consumers with bad oral hygiene. Patients were followed for 36 months after surgical treatment and postoperative radiotherapy. Genomic DNA was isolated with phenol-chloroform. Presence of p53 mutations in exons 4, 5, 6, 7 and 8 was detected by PCR/SSCP-electrophoresis. Results: p53 mutations were detected in 11 patients (26 %), out of which 2 was with mutation in exon 4 (20%), 4 in exon 5 (40%), 3 in exon 6 (30 %) and 2 in exon 7 (20%) and none in exon 8. Disease-free interval (DFI) of these patients ranged from 4 to 36 months. DFI in pts with p53 mutations ranged from 5 to 18 months (mean 7.9 months) while in the patients without p53 mutations it ranged from 4 to 36 months (mean 29.2 months). Conclusion: Our results obtained in the relatively small group of patients show firm correlation between p53 mutations and clinical course of disease. These findings need further confirmation on the larger group of patients.

Reports about the frequency of odontogenic tumors are scarce, and diagnostic criteria used in the reports are not uniform. This article presents the results of a retrospective study of odontogenic tumors recorded in four services of diagnostic pathology in Mexico City (two dental schools, one cancer hospital, and one private oral pathology service). The final diagnosis in each case was based on the 1992 histologic criteria of the World Health Organization. The frequency of odontogenic tumors, expressed as a percent of all oral and maxillofacial specimens, ranged from 0.8% in the cancer hospital (0.02% of all biopsies) to 3.7% in the private oral pathology service. The frequency was identical for the two dental schools (2.5%). We found a total of 349 odontogenic tumors; of these, 345 were benign (98.8%), and 4 (1.1%) were malignant (3 were primary intraosseous carcinomas and 1 was a malignant ameloblastoma). The most frequently occurring tumors were odontoma (34.6%), ameloblastoma (2...