Myoepithelial cells' role in the development of complex and mixed tumors in canine mammary gland [Rol de las células mioepiteliales en el desarrollo de tumores complejos y mixtos de la glándula mamaria canina]
Rosciani A.S.,Servicio de Diagnostico Histopatologico y Citologico |
Merlo W.A.,Servicio de Diagnostico Histopatologico y Citologico |
Insfran R.M.,Servicio de Diagnostico Histopatologico y Citologico |
Benitez J.S.,Servicio de Diagnostico Histopatologico y Citologico |
Ortega H.H.,Cat. Biologia Celular
Revista Veterinaria | Year: 2010
Myoepithelial cells (MEC) proliferate in complex and mixed canine mammary gland tumors. They usually transform into cells from myxoid, chondroid and bone tissues. Different attempts to characterize and make them evident have been made, by using specific markers. Myoepithelial cells suffer phenotypic transformations during proliferation, and different types of such transformations have been described: fusiform, hypertrophic, stellate and rounded myoepithelial cells and chondroblasts. The purpose of this assay is to present the results from the proliferation cells' nuclear antigen (PCNA) and alpha smooth muscle actin (AA) double immunohistochemical technique, which revealed CME proliferation. In addition, to report the description of morphologically identified MEC's varieties on hematoxilin and eosine slides. Fifty four canine mammary tumours diagnosed as simple (SC) and complex carcinomas (CC), and carcinomas in mixed benign tumours (CMT), were studied. The five MEC's varieties (previously described by other authors, were recognized. All types, except for chondroblasts and or osteocytes, were observed in CC, whereas all of them were seen in CTM. SC showed the presence of fusiform and hypertrophic MEC. Positive AA cytoplasmic staining pattern was seen in the all of fusiform and hypertrophic MEC. Less than 50% of stellate MEC was weakly reactive. No positive rounded MEC were observed. Chondroblasts and osteocytes were observed with a weak stain only in two occasions. CC (17,33) and CTM (15,67) showed the highest PCNA reactive MEC's nucleus counts over SC (12,56), although no significant statistics differences were found. These findings are in agreement with the current presumption that MEC proliferate, transform and give rise to different tissues such as fibrous, myxoid and chondroid.