Clinicopathological aspects of 25 cases of sialolithiasis of minor salivary glands.

Sialolithiasis of minor salivary glands (SMSG) is rarely reported and presumably represents an underestimated disease. This study examined the clinicopathological aspects of 25 selected SMSG cases over an 11-year period at the Oral Pathology Department of the University of Sao Paulo, Brazil. SMSG was not a clinical diagnosis in 92% of the cases. Histologically, the sialoliths tended to be superficial and formed by concentric layers with variable degrees of mineralization. Chronic periductal and parenchymal inflammation were frequent, as well as squamous metaplasia of the affected duct. Ectasia, squamous and mucous metaplasia, mucous plug formation, and cellular debris were seen in adjacent ducts. Clinicians should be aware of SMSG, especially with regard to its higher incidence in the upper lip and buccal mucosa.

Heterotopic gastrointestinal mucosa in the oral cavity of adults.

Heterotopic gastrointestinal mucosa (HGM) is a rare entity observed in the head and neck region and occurs more frequently in male infants and children. The floor of the mouth and anterior aspects of the tongue are the most commonly affected sites. Histologically, HGM resembles gastric, intestinal or colonic mucosa with areas of squamous epithelium, which can be cystic or solid. In the current report, 2 cases of HGM affecting the oral mucosa in patients over 35 years of age are presented, and one of these cases presented 2 nodules in different locations. Both cases represented solid lesions instead of the more common cystic presentation showing gastric glandular-type tissue that was lined with pseudostratified columnar epithelium containing crypts and fundic glands. Immunohistochemical analysis revealed positive expression of cytokeratins 7, 8 and 18 and smooth muscle actin (SMA). In both cases, the final diagnosis was HGM, and conservative surgical excision was performed.

Correlation between c-Jun and human papillomavirus in oral premalignant and malignant lesions.

c-Jun, one of the components of the transcription factor activating protein-1 (AP-1), is suggested as a factor in malignant progression of oral lesions. c-Jun and other AP-1 components relationships with human papillomavirus (HPV) infection have been investigated, but not yet focusing on oral carcinogenesis. The aim of this study was to verify whether c-Jun immunohistochemical expression is related to HPV DNA detection in oral premalignant and malignant lesions. Fifty cases diagnosed as oral leukoplakias, with different degrees of epithelial dysplasia, and as oral squamous cell carcinomas (OSCC) were submitted to immunohistochemistry to detect c-Jun and to in situ hybridization with signal amplification to assess HPV DNA. It was verified that c-Jun nuclear expression increased according to the degree of dysplasia within the lesion, with the greatest expression in OSCC. The same did not happen concerning HPV infection--a discrete proportional relation was observed in indexes found in leukoplakia with no dysplasia, leukoplakia with dysplasia and OSCC, but statistically insignificant. When separating the group of leukoplakia by degrees of dysplasia, this relation of proportion was not observed. Nevertheless, the overall prevalence of HPV infection was 24% and the high-risk HPV types were the most frequently identified, which does not allow excluding HPV as a risk factor in oral carcinogenesis. When relating c-Jun expression and HPV infection, no statistically significant relationship is observed. Results suggest then that malignant progression mediated by c-Jun is independent of the presence of HPV in oral carcinogenesis.

Evaluation of proliferative potential in oral lichen planus and oral lichenoid lesions using immunohistochemical expression of p53 and Ki67.

A small proportion of cases diagnosed as oral lichen planus (OLP) and oral lichenoid lesions (OLL) can undergo malignant transformation. Some authors, however, stand that only dysplastic lichenoid lesions, not true OLP, have the potential to progress to oral squamous cell carcinoma (OSCC). The histologic diagnosis is a subjective resource and is not always accurate in differentiating OLP from OLL. Thus, this study attempted to evaluate the malignant potential of lesions diagnosed as OLP and as OLL without dysplasia. The Streptavidin-biotin method of immunohistochemistry was used for the staining with p53 and Ki67 in 22 cases of OLP and 27 cases diagnosed as OLL. Ki67 immunoexpression was not statistically different between OLP and OLL (p = 0.353), but, p53 staining showed a significant contrast (p = 0.036). A higher average of staining was detected in the group of OLP. The study showed that apparently a diagnosis of OLP or OLL makes no difference for the patient regarding malignant transformation, although in OLP p53 showed a higher index of expression, probably related to the intensity of inflammatory infiltrate.

Assessment of c-Jun, c-Fos and cyclin D1 in premalignant and malignant oral lesions.

UNLABELLED: Some oral cancers are known to develop from dysplastic oral epithelium. In the present study, the expression of c-Jun, c-Fos, and cyclin D1 proteins in oral epithelial lesions with different degrees of dysplasia, and in oral squamous cell carcinomas (OSCCs) was evaluated. Eighteen cases of mild dysplasia, 23 cases of moderate to severe dysplasia and 24 OSCCs were studied immunohistochemically. Additionally, 15 sections of oral mucosa without any evidence of dysplasia were included in the study. RESULTS: c-Jun expression increased according to the degree of oral dysplasia, with the greatest expression found in OSCC. c-Fos expression was intense in normal mucosa, reduced in mild dysplasia and high in moderate to severe dysplasia and in OSCCs. Cyclin D1 was expressed in only a few cases of moderate to severe dysplasia and in most of the OSCCs. Statistical analysis showed a correlation between the three proteins and the degree of epithelial alteration. The present results indicate a possible role of c-Jun and c-Fos in malignant transformation of oral mucosa.

Comparison between immunohistochemical expression of cyclin D1 and p21 and histological malignancy graduation of oral squamous cell carcinomas.

The objective of the present study was to correlate the expression of cyclin D1 with the expression of p21 in 28 cases of oral squamous cell carcinoma (OSCC), as well as to compare the expression of both with a histological graduation of this neoplasm. Immunohistochemistry was used to obtain the expression of cyclin D1 and p21. The results of statistical analysis showed no correlation between the expression of cyclin D1 and p21. Also, there was no correlation between the mean numbers of cyclin D1 positive nuclei and p21 positive nuclei and the histological scores of malignancy. However, the marked expression of cyclin D1 in high-grade tumors supports its role in proliferative activity. In contrast, p21 seems unable to arrest tumor progression in OSCC.

Compound odontoma in three dogs.

Three young, female dogs were operated for compound odontoma. All tumors were considered stage III with treatment consisting of partial mandibulectomy or maxillectomy. Microscopic examination of the resected tissue confirmed the diagnosis. Relatively aggressive, resective surgery resulted in prolonged tumor-free intervals.

Immunohistochemical study of the orthokeratinized odontogenic cyst: a comparison with the odontogenic keratocyst.

OBJECTIVE: Orthokeratinized odontogenic cyst (OOC) is a developmental cyst that occurs in the maxilla and the mandible and is defined by the World Health Organization as the uncommon orthokeratinized type of odontogenic keratocyst (OKC). However, studies have shown that OOC has peculiar clinicopathologic aspects and biologic behavior when compared with other developmental odontogenic cysts, especially OKCs. Therefore, in this study, the immunohistochemical profile of the OOC was delineated and compared with that of the OKC. STUDY DESIGN: Twelve cases of OOC were submitted to a panel of antibodies composed of cytokeratins (10, 13, and 14) and extracellular matrix proteins: fibronectin, types I and III collagen, and tenascin. For comparative means, 12 cases of OKC also were submitted to the same panel of antibodies. RESULTS: The results obtained showed that OOCs expressed cytokeratin 10 and showed variable expression of cytokeratins 13 and 14. Fibronectin and collagen types I and III also were expressed in OOC in a fibrillar aspect. OKC showed only the superficial keratin layer positive to cytokeratin 10 and the basal and suprabasal layers with variable expression of cytokeratin 14, and cytokeratin 13 was present in the upper epithelial layers. The extracellular matrix proteins showed a nonfibrillar expression. Tenascin was immunoexpressed only in OKC. CONCLUSION: The immunohistochemical profile of the studied cysts clearly showed that OOC presents a well-formed cystic enveloping, whereas the OKC profile is compatible with a more aggressive biologic behavior.

Immunolocalization of c-Fos and c-Jun in human oral mucosa and in oral squamous cell carcinoma.

BACKGROUND: Studies have addressed the relevance of c-Jun and c-Fos proteins in cancer development. In the present study, the expression of c-Jun and c-Fos, the major components of transcription factor activator protein (AP1), were evaluated to determine possible alterations to these factors in oral squamous cell carcinoma (OSCC). METHODS: Fifteen cases of normal oral mucosa and 20 cases of OSCC were retrieved from the Archives of the Surgical Pathology Service at the University of São Paulo. The samples of normal oral mucosa or OSCC originated from different oral mucosal sites. Tissues were submitted for immunohistochemical analysis to detect c-Jun and c-Fos proteins. The OSCC was classified as well, intermediate or poorly differentiated. RESULTS: The results showed that both c-Jun and c-Fos are expressed in normal oral mucosa and in OSCC. In normal mucosa, immunoreactivity for c-Jun was detected in the cytoplasm of the upper basal layers, while in OSCC, c-Jun was detected in the nuclei of the cells. C-Fos expression was observed in the nuclei of cells, both in normal mucosa and in OSCC, but its expression varied according to the cell layer in normal mucosa, and the differentiation of OSCC. CONCLUSIONS: The nuclear expression of c-Jun in OSCC, in contrast to its cytoplasmic expression in normal oral mucosa, indicates that c-Jun may have a role in the development of oral cancer. In contrast, the absence of both c-Jun and c-Fos in poorly differentiated carcinoma might be useful in understanding the cell cycle events important in uncontrolled cell growth.