Clinicopathological prognostic factors of oral tongue squamous cell carcinoma: a retrospective study of 202 cases.

Although several histopathological parameters and grading systems have been described as predictive of the treatment response and outcome of oral squamous cell carcinoma (OSCC), none is universally accepted. A new scoring system, the histological risk model, was recently described to be a powerful predictive tool for recurrence and overall survival in OSCC. The aim of this study was to verify the predictive role of the histological risk model in a cohort of 202 patients at all stages of oral/mobile tongue squamous cell carcinoma (OTSCC). Demographic and clinical data were collected from the medical records and the tumours were evaluated using the histological risk model. Statistical analyses were performed using the χ(2) test, the Kaplan-Meier method, and the Cox regression model. The histological risk model showed no statistical correlation with demographic or clinical parameters and did not Predict the outcome of the OTSCC patients. However, multivariate regression analysis revealed a significant correlation of the clinical disease stage with the disease outcome. Despite major efforts to identify new predictive parameters and histological systems, clinical features are still the most reliable prognostic factors for patients with OTSCC.

Analysis of the frequency and nature of hyaline ring granulomas in inflammatory odontogenic cysts.

AIM: To determine the prevalence of hyaline ring granulomas (HRGs) in a large case series of inflammatory odontogenic cysts, and to investigate the nature of these structures. METHODOLOGY: All records from the patients diagnosed with inflammatory odontogenic cysts between January 1970 and April 2009 were reviewed. Histologic sections were evaluated by light microscopy and cases with HRGs for which sufficient biological material was available were submitted to histochemical analysis (Masson's trichrome) and immunohistochemistry (CD34, CD68 and collagen IV). RESULTS: Twenty-two (3.3%) of the 661 cases of inflammatory odontogenic cysts diagnosed during the study period presented HRGs. The relative frequency of HRGs was higher amongst residual radicular cysts (6.1%), followed by paradental cysts (5.6%) and radicular cysts (3.0%). HRGs appeared as roughly circular homogeneous/fibrillar masses in 14 (63.6%) cases and as round structures enclosing amorphous material in 3 (13.6%) cases. Most (77.8%) roughly circular homogeneous/fibrillar masses were positive for collagen, whereas all (100.0%) round structures enclosing amorphous material were negative for this protein. Immunohistochemistry showed that most mononucleated cells and all multinucleated giant cells were positive for CD68, but negative for CD34, in all cases. In addition, collagen IV immunostaining was negative in amorphous structures and weakly positive in homogeneous/fibrillar masses. CONCLUSIONS: The present results suggest a very low frequency of HRGs in inflammatory odontogenic cysts and support the hypothesis that these structures arise from the implantation of foreign material, most likely food particles of plant or vegetable origin. The diverse microscopic features of HRG possibly represent different developmental stages of this structure.

Hyperplasia of myoepithelial cells expressing calponin during atrophy of the rat parotid gland induced by duct ligation.

The number and location of myoepithelial cells in the rat parotid gland submitted to surgical ligation of its main excretory duct were studied through immunohistochemical labelling for calponin. These cells were labelled by the streptavidin-biotin method using anti-calponin primary antibody, and their number was determined during each step of glandular atrophy, i.e., at time zero (control) and 1, 7, 15, 21, 30 and 60 days after ligation. Morphological analysis showed a gradual decrease and fibrosis of the glandular lobules accompanied by disappearance of the acini and the occurrence of duct-like structures. The expression of calponin was observed in all specimens analysed, being restricted to myoepithelial cells. Labelling revealed the distribution of myoepithelial cells around the acini and intercalated ducts in the control group and around duct-like structures later during the course of atrophy. Quantitative analysis demonstrated significant increase in the number of myoepithelial cells up to day 7 post-ligation, followed by gradual increases which, however, were not statistically significant. These results suggest that myoepithelial cells proliferate intensely up to day 7 post-ligation, an event that coincides with a higher rate of disappearance of acinar cells. After this period, the elevatednumber of cells observed at the end of the previous period is maintained.