MUC-1 expression in pleomorphic adenomas using two human milk fat globule protein membrane antibodies (HMFG-1 and HMFG-2)

Pleomorphic adenoma (PA) is the most common salivary gland tumor and its microscopic features and histogenesis are a matter of debate. Human milk fat globule protein membrane (HMFG) monoclonal antibodies (MoAbs) comprise a set of antibodies against the mucin 1 (MUC-1) protein detected in several salivary gland tumors. Objective The aim of this study was to assess the immunoexpression of the PA neoplastic cells to MUC-1 protein using HMFG-1 and HMFG-2 MoAbs, contrasting these results with those from normal salivary gland tissue. Material and Methods Immunohistochemical detection of MUC-1 protein using HMFG-1 and HMFG-2 MoAbs was made in 5 mm thick, paraffin embedded slides, and the avidin-biotin method was used. Results Positivity to HMFG-1 and HMFG-2 MoAbs was found in ductal, squamous metaplastic and neoplastic myoepithelial cells, keratin pearls and intraductal mucous material. Two kinds of myoepithelial cells were identified: classic myoepithelial cells around ducts were negative to both MoAbs, and modified myoepithelial cells were positive to both MoAbs. This last cellular group of the analyzed tumors showed similar MUC-1 immunoexpression to ductal epithelial cells using both HMFG antibodies. Intraductal mucous secretion was also HMFG-1 and HMFG-2 positive. Conclusions Our results showed there are two kinds of myoepithelial cells in PA. The first cellular group is represented by the different kinds of neoplastic myoepithelial cells and is HMFG-positive. The second one is HMFG-negative and represented by the neoplastic myoepithelial cells located around the ducts. .

Immunohistochemical study of androgen, estrogen and progesterone receptors in salivary gland tumors

The aim of this work was to study the immunohistochemical expression of androgen receptor, estrogen receptor and progesterone receptor in pleomorphic adenomas, Warthin's tumors, mucoepidermoid carcinomas and adenoid cystic carcinomas of salivary glands. A total of 41 pleomorphic adenomas, 30 Warthin's tumors, 30 mucoepidermoid carcinomas and 30 adenoid cystic carcinomas were analyzed, and the immunohistochemical expression of these hormone receptors were assessed. It was observed that all cases were negative for estrogen and progesterone receptors. Androgen receptor was positive in 2 cases each of pleomorphic adenoma, mucoepidermoid carcinoma and adenoid cystic carcinoma. In conclusion, the results do not support a role of estrogen and progesterone in the tumorigenesis of pleomorphic adenomas, Warthin's tumors, mucoepidermoid carcinomas and adenoid cystic carcinomas. However, androgen receptors can play a role in a small set of salivary gland tumors, and this would deserve further studies.

Expressão imuno - histoquímica de p53 na discriminação do comportamento biológico dos tumores de glândulas salivares / Immunohistochemical expression of p53 on the biological behavior of salivary gland tumors

INTRODUÇAO: Mutações no gene TP53 têm sido identificadas em várias neoplasias, incluindo as de glândulas salivares (NGS). Entretanto não existe consenso sobre o significado biológico da expressão de p53 nessas lesões. OBJETIVOS: Avaliar a marcação imuno-histoquímica do antígeno p53 em NGS, investigando possíveis diferenças entre lesões benignas e malignas, entre diferentes tipos histológicos e entre tumores malignos que: 1) não desenvolveram metástases; 2) emitiram metástases; e 3) metástases de NGS. MATERIAL E MÉTODO: Foram avaliados 16 casos de adenomas pleomórficos (AP), 17 lesões malignas que não apresentaram metástase durante a proservação (sete carcinomas adenóides císticos [CAC] e dez mucoepidermóides [CM]), 13 tumores malignos que emitiram metástases (nove CAC e quatro CM) e, ainda, 12 metástases regionais ou distantes (cinco CAC e sete CM). Por marcação imuno-histoquímica (estreptavidina-biotina-peroxidase), índices médios de localização do antígeno p53 foram estabelecidos para cada tumor. Para análise, utilizaram-se testes de Mann-Whitney e Kruskal-Wallis, com nível de significância de 5 por cento. RESULTADOS: Foram observadas diferenças estatisticamente significantes nos índices médios de imunomarcação de p53 entre lesões benignas e malignas (p = 0,03) e entre os diferentes tipos histológicos, notadamente entre o AP e o CM (p = 0,02). Todavia houve marcada sobreposição dos intervalos de índices de expressão entre os grupos testados. Nenhuma diferença de expressão foi observada entre as neoplasias malignas quanto ao seu comportamento metastático. CONCLUSAO: Embora a expressão de p53 tenha sido detectada em todos os subtipos de NGS, a marcação imuno-histoquímica deste antígeno não permitiu discriminar os tumores malignos quanto ao seu comportamento biológico.

Myoepithelioma. A case report.

A rare case of oral myoepithelioma is reported. The tumour was composed of plasmacytoid type of myoepithelial cells. These plasmacytoid cells or hyaline cells exhibited a diffuse positivity for pancytokeratin, S-100 and vimentin in their cytoplasm. Studies have to be performed in order to find out whether the myoepithelial cells M.E. of plasmacytoid type are true M.E. cells of not.

Prenatal development of human major salivary glands. Histological and immunohistochemical characteristics with reference to adult and neoplastic salivary glands

No abstract available.