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.

The aim of this study is to record prevalence of oral mucosal alterations in adult patients , who were attended in the clinics of the faculty of Odontology , National Autonomous University of México in México City. Clinical examination were made by specialists in Oral Pathology, this sample consisted in 1152 subjects reviewed in 9 months duration clinical trial; 754 patients were females (64.45%) and 398 males (34.55%) age range 18-84 yr. and a mean age of 39 yr ±15.12. We record 32 different diagnosis, 18 patients (1.6%) had any lesion. The more prevalent lesions were: White fricctional lesions 354 cases (30.72%), traumatic ulcer 132 (11.45%) and tissue growing as response to aparent cause 130 (11.28%). The more common condition were: Melanoplakia 694 cases (60.24%), Fordyce granules 634 (55.03%) and fissured tongue 428 (37.15%). Our findings are compared with data on the prevalence of intraoral lesions in different countries.

El objetivo de este estudio fue determinar la distribución de condiciones y lesiones de la mucosa bucal de pacientes que asistieron a las clínicas de admisión de la Facultad de Odontología de la Universidad Nacional Autónoma de México. El examen clínico lo realizaron 5 especialistas en Patología Bucal previamente calibrados. El total de pacientes examinados fue de 1 152 en un período de 9 meses: 754 mujeres (65,45 %) y 398 hombres (34,55 %), con un rango de edad entre 18 y 84 años (39 años como promedio). Se incluyeron en el estudio32 condiciones y lesiones; las definiciones operacionales se basaron en los criterios establecidos en la Guide to epidemiology and diagnosis of oral mucosal diseases and conditions de la OMS. Del total de pacientes, únicamente 18 (1,6 %) no presentaron ninguna alteración. Las lesiones más frecuentemente diagnosticadas fueron: lesión blanca friccional con 354 casos (30,72 %), úlceras traumáticas con 132 (11,45 %) y aumento tisular con causa aparente con 103 (11,28 %). Las condiciones más comunes fueron: melanosis racial con 694 casos (60,24 %), gránulos de Fordyce 634 (55,03 %) y lengua fisurada 428 (37,15 %). En este estudio encontramos que las condiciones y lesiones se incrementan con la edad observándolas entre la 3ra. y 5ta. décadas de la vida.

Objective: The aim of this study was to quantify by immunohistochemistry the number of myoepithelial cells (MyECs) in pleomorphic adenomas (PAs). Material and methods: We retrieved the paraffin cubes of 27 PAs, new slides were done and they were stained with anti-S100 protein antibody. The amount of S-100 protein positive cells was quantified, their morphology was recorded and comparison among MyEC number with age, gender and involved gland were also done. Results: With S-100 protein, MyECs in normal salivary gland tissue were seen surrounding the ductual structures only. In the analysed PAs a mean of 27.4% of the neoplastic cells were positive to the antibody. With the exception of one PA, in all the analysed cases the plasmacytoid cells were the most commonly identified cells (48,6%). Conclusions: Results of this study suggest that MyECs do not constitute the main cellular component of the neoplastic compartment in PAs and corroborate the previously reported evidence by different au-thors, who studying the PAs suggested that MyECs does not comprise the main cellular neoplastic component of these entities.

Objetivo: El objetivo de este estudio fue cuantificar por medio de inmunohistoquí-mica el número de células mioepiteliales (CMs) en adenomas pleomorfos (APs). Material y Métodos: Se recuperaron los cubos de 27 APs y se hicieron nuevas laminillas, las que se tiñeron con un anticuerpo anti-proteína S-100, se contó el número de células S-100 positivas, se registró su morfología y se hicieron comparaciones del número de CMs tomando en cuenta el sexo, edad y glándula de origen. Resultados: Se observó que en el tejido glandular normal, las CMs solo se observaron alrededor de las estructuras ductuales. En los APs analizados se encontró que en promedio, solamente el 27,4% de las células neoplásicas fueron positivas a este anticuerpo. Con excepción de un AP, en todos los casos analizados las células plasmocitoides fueron las células más comúnmente encontradas (48,6%). Conclusiones: Los resultados de este estudio sugieren que las CMs no forman el componente celular principal del compartimiento neoplásico de los APs y confirman las evidencias encontradas desde hace varios años, por diferentes autores, quienes estudiando los APs, sugirieron que las CMs no forman la mayor parte de las células neoplásicas en estas entidades.