Immunohistochemical expression of Mdm2 in polymorphous low-grade adenocarcinoma [PLGA] of salivary glands

Histologic diversity is an intrinsic feature to salivary gland tumors but it is a particular feature to polymorphous low grade adenocarcinoma [PLGA] which is a histologically low grade tumor of minor salivary gland origin with an infiltrative growth pattern. The present study was carried-out to investigate the immunohistochemical expression of murine double minute 2 [Mdm2] protein in PLGA of salivary glands. Thirteen archival paraffin block of PLGA cases were processed immunohistochemically to detect the Mdm2 reactivity. Only eleven cases from the studied PLGA cases were reactive to Mdm2 [73.3%]. The predominantly solid form with ductal differentiation and the predominantly papillary cystic form revealed the lowest Mdm2 reactivity [15% and 20.5% respectively]. The ductal-tubular from cases revealed 49% reactivity of their cells of Mdm2. The cribriform pattern cases had the highest Mdm2 reactivity [76.5%]. In conclusion, various histological patterns of PLGA expressed Mdm2 protein in different percentages, this variation suggests a different behavior of cells in various patterns of PLGA and also suggest a diagnostic role of Mdm2 to differentiate varieties of PLGA with high and those with low prolifrative activity

Demonstration of the HER-2/neu oncogene by immunohistochemical analysis in salivary gland carcinomas

Anti-HER-2/neu agents are currently under investigation in phase II and III trials as a radiosensetizers in patients with malignant salivary gland tumors, these factors are also able to reduce tumor cell growth by inducing apoptosis and to modulate inhibition of production of angiogenetic factors. Therefore it's important that tumor is evaluated to identify patients who might benefit from this therapeutic approach, so the present study was carried out to evaluate the immunohistochemical expression of HER-2/ neu oncogene in different salivary gland carcinomas [SGC]. The present study was carried-out to evaluate the immunohistochemical expression of HER-2/ neu oncogene in different salivary gland carcinomas [SGC]. The present study was carried-out on 25 archival paraffin blocks of SGC cases, from each paraffin block, 5 microns thick section was stained with hematoxylin and eosin stain for microscopical diagnosis and grading of the studied cases, another section was processed to detect the immunohistochemical expression of HER-2/ neu protein. Twenty one cases [84%] out of the studied 25 SGC cases expressed HEF-2/ neu protein and the remaining 4 negative cases were diagnosed as polymorphous low grade adenocarcinoma [PLGA], all the studied mucoepidermoid and acinic cell carcinoma cases were positive for anti-HER-2/ neu antibody. The HER-2/neu protein expression was more prominent in high grade SGC cases. The findings of the present work potentiate the role of anti- HER-2/ neu agents a recent treatment for SGC and strongly recommends SGC testing for HER-2/ neu positivety to predict the response to anti HER-2/neu therapy as well as its potential impact on responses to the standard type of therapy

Corelation between epithelial proliferation and inflammation in odontogenic cysts

The present study was carried-out to investigate the proliferative potential of the epithelium of different types of odontogenic cysts [OC] using immunohistochemical staining against proliferating cell nuclear antigen [PCNA] as a marker of proliferation and to investigate its correlation to inflammation . This study was carried-out on 19 archival paraffin blocks of odontogenic cyst cases, from each case two 5 microns thick sections were processed for immunohistochemical study of PCNA, which was counted in 10 high power fields [HPF] and compared to the number of inflammatory cells in the sub epithelial connective tissue. In the present study radicular cysts presented Scases [42.1%], 7 keratocysts [36.8%] and 4 dentigerous cyst cases [21.1%]. Three radicular cysts [15.8%] were completely negative for immunohistochemical staining against PCNA, the remaining 16 cases had 26.4 PCNA positive cells / 10 HPF. Mean number of PCNA positive cells for cases of dentigerous cysts was 30.9 cells/10 HPF followed by keratocysts 26.1 cells/10 HPF and then radicular cysts 22.3 cells/10 HPF, the differences between these groups was statistically insignificant. On the other hand, mean number of inflammatory cells per 10 HPFs showed statistically significant differences between the studied three types of cysts [P = 0.002]. Strong positive significant correlation between mean number of PCNA positive cells and inflammatory cells was reported in the present study for all the studied cyst cases and for each individual cyst type. The results of the present study demonstrated a strong positive correlation between proliferation and inflammation in all types of the studied odontogenic cyst cases

Treatment of central giant cell granuloma of the mandible with intralesional injection of corticosteroid

This study was carried-out to report our experience with ten cases of central giant cell granuloma [CGCG] of the mandible treated with intralesional injection of corticosteroid with special reference to the possible effect of corticosteroid on CGCG microscopically and by DNA cytophotmetry. Ten patients with CGCG of the mandible were included in this study. Triamcinolone acetonide was injected into the lesions, the injection was repeated weekly for a total of six weeks. Panoramic radiographs were obtained every three months to evaluate the healing process. Complete regression of the lesions was proved in three patients with no evidence of recurrences during a follow-up period of one year. The other seven cases needed surgical excision, which revealed significant decrease in the number [P=0.001] and size [P=0.01] of multinucleated giant cells [MNGCs]. Whereas, no differences were reported between the number of blood vessels, DNA content and ploidy pattern of MNGCs before and after the intralesional corticosteroid injection. It could be concluded that, this form of treatment may be advantageous, particularly for large lesions in order to cure or reduce the size of the lesion and thus minimize the need for extensive surgical resection that could result in functional and esthetic deficits

Immunohistochemical study of the proliferative activity of pleomorphic adenoma by localization of proliferating cell nuclear antigen [PCNA]

Pleomorphic adenoma [PA] is one of the most common salivary gland tumors, it is still controversial if atypical tumor cells scattered in salivary PAs are precancerous and how carcinoma arises in PA. The present study was carried-out to investigate the proliferative activity of PA by an immunohistochemical localization of proliferating cell nuclear antigen [PCNA]. Seventeen PA cases, four adenocarcinoma cases and normal salivary tissue surrounding tumor areas in three PA cases were included in the present study, from each case two paraffin sections of 5 microns thickness were obtained, one section was stained with hematoxylin and eosin stain for histologic and morphometric study of PA cases, the other section was immunohistochemically processed to detect PCNA positive cells in the studied cases. Normal salivary tissue showed no reactivity to PCNA, all adenocarcinoma cases of the present study were reactive to PCNA. From 17 PA cases only 6 cases [35.3%] were reactive to PCNA, 50% of these cases [3 cases] were of the predominantly cellular PA pattern, 16.7% [one ease] was of the predominantly myxoid PA pattern and the remaining two cases [33.3%] were of the mixed cellular and myxoid PA Statistically significant difference of mean nuclear area [P=0.01] between cellular [116.8+/-27.6 microns] and myxoid areas [55.4+/-10.8 microns] in the studied PA cases was reported in the present study, meanwhile, no significant difference between mean nuclear areas of PA cases with reactive cells and those with no reactive cells to PCNA. From the findings of the present study it can be concluded that benign salivary PA contain actively proliferating cells as indicated by higher PCNA reactivity than that of normal salivary tissue, these actively proliferating cells were expressed mainly in cellular sheet- like areas of PA, they revealed no histopathologic or morphometric differences from non-reactive PA cells. These cells may be a source of recurrence after surgical removal of PA or may be a precursors for malignant cells leading to malignant transformation of benign PA