S.O.M. de Sousa

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.

Study of minor salivary gland mucoepidermoid carcinoma differentiation based on immunohistochemical expression of cytokeratins, vimentin and muscle-specific actin

The expression of cytokeratins (CKs) 7,8,10,13,14,18,19, vimentin and muscle-specific actin (MSA) was investigated in 17 mucoepidermoid carcinomas (MEC) by the streptavidin-biotin technique. The results revealed that CKs 7, 8 and 18 were positive for intermediate, luminal columnar and mucous cells. For epidermoid cells, the expression was heterogeneous and discrete. The reaction with CK19 was similar to that seen for the above CKs, except for the fact that mucous cells were negative. CK 14 was preferentially expressed in the intermediate cells localised in basal, parabasal and epidermoid cells. CK13 was localised in intermediate, epidermoid and luminal columnar cells. In stratified epithelium, CK13 was expressed in intermediate cells and negative in basal cells. These findings were more expressive in cystic areas of the tumours. CK10 was negative for all the cases studied. MSA was positive only in stromal elements, and only two cases of CME were heterogeneously positive for vimentin. The result obtained showed that the immunoprofile of MEC, for the studied antigens, is similar to that exhibited by the excretory duct of normal salivary glands.

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.

Differential expression of galectin‐3, β‐catenin, and cyclin D1 in adenoid cystic carcinoma and polymorphous low‐grade adenocarcinoma of salivary glands

BACKGROUND Galectin-3 has been implicated in tumor progression of some malignancies as thyroid, prostate, and salivary gland tumors. Recently, it has been suggested that this protein may be an important mediator of the beta-catenin/Wnt pathway. Moreover, nuclear galectin-3 expression has been implicated in cell proliferation, promoting cyclin D1 activation. Thus, the present study aimed to correlate galectin-3 expression with beta-catenin and cyclin D1 expressions in adenoid cystic carcinoma (ACC) and in polymorphous low-grade adenocarcinoma (PLGA). METHODS Fifteen formalin-fixed paraffin-embedded cases of each tumor were retrieved from the files of the Surgical Oral Pathology Service at the University of São Paulo and the proteins were analyzed by immunohistochemistry. RESULTS Adenoid cystic carcinoma showed galectin-3 immunostaining mainly in the nuclei, while PLGA revealed a positive mostly cytoplasmic reaction to galectin-3 in the largest part of tumor cells. Both tumors showed intense cytoplasmic/nuclear staining for beta-catenin in majority of cases. Cyclin D1 immunoreactivity was not detected in 14/15 PLGA and showed specific nuclear staining in 10/15 cases of ACC in more than 5% of the neoplastic cells. Cyclin D1 expression was correlated with cytoplasmic and nuclear galectin-3 expression in ACC (P < 0.05). CONCLUSIONS These results suggest that in ACC galectin-3 may play a role in cellular proliferation through cyclin D1 activation. In addition, nuclear expression of galectin-3 in ACC may be related to a more aggressive behavior of this lesion. Although beta-catenin seems to play a role in carcinogenesis in both lesions, it seems that it does not bind to galectin-3 for cyclin D1 stimulation.

Diagnostic approaches in unsuspected oral lesions of syphilis

Awareness of the increased prevalence of syphilis is essential for early diagnosis and treatment, and to prevent the spread of the disease. Although serological studies are the primary tool used to confirm the diagnosis of secondary syphilis, biopsy of unsuspected oral lesions is not uncommon in the routine oral pathology laboratory. In these cases, histopathological characteristics are likely to indicate the possibility of syphilis, and an immunohistochemical reaction can confirm it. The aim of the present study was to highlight the histological features and test the efficacy of immunohistochemistry in the detection of Treponema pallidum in oral lesions biopsied with the assumption of a non-syphilitic disease. Thirty-nine tissue samples from patients for whom the possibility of syphilis was suggested on the basis of histopathological findings, were retrieved from the surgical oral pathology service files and submitted to immunohistochemical staining for T. pallidum. The study was approved by the institutional ethics committee. Eighteen of the tissue samples were positive for T. pallidum. Following this, the contributing clinicians were contacted to check whether they had asked for serological examinations when the diagnostic report was received; for all 18 positive cases, the clinicians confirmed that the patients had tested positive at that time. This study shows the importance of clinical-pathological correlation and the value of immunohistochemistry in the diagnosis of unsuspected syphilis.

White sponge naevus: improvement with tetracycline mouth rinse: report of four cases

White sponge naevus (WSN) is a rare condition affecting the mucous membranes, especially the oral mucosa. WSN appears to follow a hereditary pattern, although cases with no family history have been reported. Genetic studies have associated the development of WSN with mutations in keratins 4 and 13. Treating WSN is still a challenge. Some benefits have been reported with the use of antibiotics such as penicillin and tetracycline. This study assessed the clinical response of WSN to 0.25% aqueous tetracycline mouth rinse. Four cases of WSN affecting three women (aged 23, 27 and 46 years) and one man (aged 24 years) were evaluated. Bilateral involvement of the buccal mucosa was seen in three patients, and the fourth presented lesions only of the labial mucosa. WSN diagnosis was based on clinical and histopathological findings (Fig. 1a,b). Treatment consisted of 0.25% aqueous tetracycline mouth rinse (5 mL for 1 min) twice daily for up to 12 weeks. Responses to the treatment are summarized in Table 1. Patients 1 and 2 were more resistant to treatment, showing only partial improvement (Fig. 2a,b). The other two patients, who had no familial members affected (cases 3 and 4), showed excellent response (Fig. 3a,b). During this treatment, one patient tested positive for Candida and was treated with nystatin. Mild recurrence was observed in one patient and was given a further short course of tetracycline, which promptly resolved the lesions. The most frequent clinical characteristic of WSN is white, thickened, folded oral mucosa, which is spongy to palpation. The epithelium is thickened, showing acanthosis with marked swelling and vacuolization throughout the

Mucus-producing adenopapillary carcinoma of minor salivary gland origin with signet ring cells and intracytoplasmic lumina

SummaryA histological and subcellular study of a mucus-producing adenopapillary carcinoma of a minor salivary gland is presented. The tumor was located on the buccal mucosa of a 36-year-old white man. Microscopic examination showed that the tumor was an invasive papillary growth with numerous signet-ring cells and mucous production. When viewed under the electron microscope, the tumor exhibited clusters of cells showing intracellular lumina and finely dispersed chromatin.