V.C. de Araújo

Application of immunohistochemistry to the diagnosis of salivary gland tumors.

A panel of antibodies composed of the cytokeratins (CKs), vimentin, and actin was applied to 114 minor salivary gland tumors to evaluate its diagnostic value. The results revealed that luminal cells of intercalated duct-like structures, such as those seen in pleomorphic adenoma, basal cell adenoma, adenoid cystic carcinoma, and epithelial-myoepithelial carcinoma, expressed CKs 7, 8, 14, and 19. The outer cells of these structures exhibited vimentin or vimentin plus muscle-specific actin, but rarely CK14, which is seen particularly in pleomorphic adenoma, in the tubular type of basal cell adenoma, and seldom in the tubular type of adenoid cystic carcinoma. Modified myoepithelial cells of pleomorphic adenoma and myoepithelioma exhibited a variable immunoprofile. CKs 7 and 8 were also observed in acinar cell adenocarcinoma and polymorphous low-grade adenocarcinoma with vimentin in the latter. CK13 was expressed only by canalicular adenoma and mucoepidermoid carcinoma cells. This study showed that the panel of antibodies employed is effective in distinguishing among salivary gland tumors.

Minor salivary gland tumours. A retrospective study of 164 cases in a Brazilian population

One hundred and sixty-four cases of intraoral salivary gland tumours retrieved from the files of the Surgical Oral Pathology laboratory of the University of São Paulo (Brazil), between 1970 and 1993, were studied. Of these, 164 tumours, 62% were classified as benign and 38% malignant. The palate was the main site of occurrence of the tumours followed by the buccal mucosa and upper lip. There was a slight predominance for female patients, with a female to male ratio of 1.3:1. The mean age for benign tumours was 39.9 years (40.8 for females, and 39.7 for males). For malignant tumours the mean age was 43.5 years (42.6 for females and 44.7 for males). Pleomorphic adenoma was the most common of the benign tumours, whereas mucoepidermoid carcinoma and adenoid cystic carcinoma were the most common malignant tumours. In general, benign tumours presented as an asymptomatic nodule. On the other hand, pain, ulceration and radiographic changes were more frequently associated with malignant lesions.

Expression of different keratins in salivary gland tumours.

Twenty-four salivary gland tumours (six pleomorphic adenomas, two myoepitheliomas, five basal cell adenomas, six adenoid cystic carcinomas and five polymorphous low grade adenocarcinomas) were investigated by an immunocytochemical technique using monoclonal antibodies against cytokeratins (CKs) 7, 8, 10, 13, 14, 18 and 19. The luminal cells of ductal structures of the tumours reacted with all the CKs studied except for CK 13 and CK 10 and sometimes CK 14, showing an immunoprofile comparable to that of the intercalated segment of a normal salivary gland. The outer cells of the ducts rarely stained with CK 14, confirming that full differentiation of the myoepithelial cells is seldom achieved in tumours. Considerations were made regarding the intriguing expression of CK 14, the heterogeneous expression of CKs in the modified myoepithelial cells and the immunoprofile of the polymorphous low-grade adenocarcinoma.

Vimentin as a marker of myoepithelial cells in salivary gland tumors

SummaryThirty-six salivary gland tumors from the Surgical Oral Pathology Service of the University of São Paulo, School of Dentistry, have been examined by immunostaining, using commercially available antibody to vimentin. The samples analyzed included tumors in which the participation of myoepithelial cells as a tumoral component has been postulated, i.e., pleomorphic adenoma, myoepithelioma, epithelial-myoepithelial adenoma, monomorphic adenoma, adenoid cystic carcinoma, epithelial-myoepithelial carcinoma, and polymorphous low-grade adenocarcinoma. Our results strongly support the view that vimentin is one of the earliest indicators of neoplastic myoepithelial differentiation.

Substance P regulates the expression of matrix metalloproteinases and tissue inhibitors of metalloproteinase in cultured human gingival fibroblasts

BACKGROUND AND OBJECTIVE Substance P may play a role in the pathogenesis of periodontal disease; however, its mechanisms of modulation are not clear. This study evaluated the effect of two concentrations of Substance P on the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in cultured human gingival fibroblasts. MATERIAL AND METHODS Fibroblasts were stimulated for 48 h with 10(-4) or 10(-9) m Substance P; untreated fibroblasts served as controls. The expression of MMP-1, -2, -3, -7 and -11 and of TIMP-1 and -2 was evaluated using real-time polymerase chain reaction and western blotting. RESULTS There was a significant, concentration-dependent stimulatory effect of Substance P on MMP-1, -2, -3 and -7 and TIMP-2 gene expression (p < 0.05), and a probable effect on MMP-11 (p = 0.06). At the higher concentration (10(-4) m Substance P), MMP-1, -2, -3, -7 and -11 and TIMP-2 showed the greatest up-regulation; at the lower concentration (10(-9) m Substance P), MMP-1, -3 and -7 and TIMP-2 exhibited diminished up-regulation, with MMP-2 and -11 showing down-regulation (p < 0.05). Expression of TIMP-1 was not affected by Substance P (p > 0.05). Western blotting confirmed that Substance P up-regulated MMP-1, -2, -3 and -11 and TIMP-2. MMP-1, -3 and -11 and TIMP-2 showed greater up-regulation at the higher Substance P concentration and diminished up-regulation at the lower concentration. MMP-2 was up-regulated to a similar degree at both Substance P concentrations. CONCLUSION In gingival fibroblast cells, Substance P at the higher concentration (10(-4) m) induced greater up-regulation of MMP-1, -3 and -11 and TIMP-2 expression, but at the lower concentration (10(-9) m) induced diminished up-regulation, which may represent a mechanism for modulating periodontal breakdown.

Immunohistochemical study of acinic cell carcinoma of minor salivary gland

Acinic cell carcinoma (ACC) is a rare salivary gland tumour, making up 4% of all minor salivary gland tumors. Typically, it is composed of acinic cells although transitional and duct-like cells are also identified. In the present study, a panel of antibodies was applied to eight minor salivary gland ACCs. Antibodies tested were: cytokeratins 7, 8, 13, 14, 18, 19, vimentin and actin (HHF35). Immunohistochemical staining revealed that cytokeratin 8, among the tested antibodies, was the more specific to neoplastic cells with a pattern of distribution quite variable and peculiar. This staining may be useful in the recognition of neoplastic acinic cells.

Vimentin in oral squamous cell carcinoma.

SummaryThe relationship between the histological grading of malignancy and the expression of vimentin and cytokeratin was studied in 43 cases of oral squamous cell carcinoma. Immunohistochemical analysis was carried out with the avidin-biotin method using monoclonal antibody anti-vimentin, and the peroxidase anti-peroxidase method using the polyclonal antibody anti-cytokeratin. All cases were classified according to the histological malignancy grading system proposed by Anneroth. All of the carcinomas were found to express cytokeratin, while 60.4% expressed vimentin. Vimentin was particularly noted in all tumors scored to have highly malignant cells.

p53 in biopsies of oral squamous cell carcinoma. A comparative study with a malignancy grading system

The relationship between the histological grading of malignancy and p53 protein expression was studied in 40 biopsies of oral squamous cell carcinomas. An immunohistochemical analysis was carried out using the streptavidin method preceded by a treatment with citric acid in a microwave oven. All cases were classified according to the histological malignancy grading system proposed by Anneroth et al. (Scandinavian Journal of Dental Research 1987, 95, 229-249). The expression of p53 was found in 62.5% of the carcinomas studied. Positivity of p53 staining showed a correlation with the histological grade of malignancy and with the degree of keratinisation, nuclear polymorphism and number of mitoses.

Well-differentiated liposarcoma of the tongue

Intraoral liposarcomas are rare, with most reported cases being of the myxoid histological type. We present a well-differentiated liposarcoma of the tongue, in a 65-year-old man. The tumour presented lipoblasts in various stages of differentiation, lipocytes in different sizes and shapes, mesenchymal and signet-ring cells. Lipoma, spindle-cell lipoma, myxoma, hibernoma, angiolipoma, fibrolipoma, pseudosarcomatous faciitis and malignant hysticytoma were considered in the diagnosis process. The patient was treated surgically and so far is free of disease.

Salivary duct carcinoma: cytokeratin 14 as a marker of in-situ intraductal growth

Aims:  The aim of this study was to determine the immunoprofile of salivary duct carcinoma and to differentiate intraductal growth from invasive growth.