ABSTRACT
RESUMEN: El carcinoma mioepitelial es una rara neoplasia maligna de las glándulas salivales; puede originarse de novo o desarrollarse en un adenoma pleomórfico preexistente o un mioepitelioma. Las características histológicas e inmunohistoquímicas de un caso de carcinoma mioepitelial de glándula parótida originado por la transformación maligna de un adenoma pleomórfico primario previo se investigaron en este trabajo. Se demostró la presencia de mitosis, pleomorfismo nuclear, áreas necróticas, mioepiteliocitos con una marcación con p63 superior al 75 % y un índice proliferativo de 15 %, características que pueden desencadenar un desenlace adverso. Resulta clave el examen periódico de la paciente que dará una probabilidad superior de curación y sobrevida y de investigar eventuales recurrencias o metástasis.
ABSTRACT: Myoepithelial carcinoma is a rare malignant neoplasm of the salivary glands; it may originate de novo or develop into a pre-existing pleomorphic adenoma or myoepithelioma. The histological and immunohistochemical characteristics of a case of myoepithelial carcinoma of the parotid gland originated by the malignant transformation of a previous primary pleomorphic adenoma were investigated in this work. The presence of mitosis, nuclear pleomorphism, necrotic areas, myoepitheliocytes with a p63 labeling greater than 75 % and a proliferative index of 15 % were demonstrated, characteristics that can trigger an adverse outcome. The periodic examination of the patient is essential, which will give a higher probability of cure and survival and to investigate eventual recurrences or metastases.
ABSTRACT
The myoepithelial cell seems to play an important role as a tumor suppressor in the development of carcinoma ex pleomorphic adenoma. Nevertheless, interesting aspects concerning the other side of the coin, i.e., the contribution of the myoepithelial cell to cell proliferation, were brought to light. Here we highlighted the studies in which myoepithelial cells were presented as tumor suppressors and promoters in the context of PA malignant transformation. In conclusion, even if in a paracrine way, divergent signals can alter the suppressor role of the myoepithelial cell and induce it to compose a microenvironment propitious to the tumor progression of the malignant cells. This would cause myoepithelial cells to succumb and malignant epithelial cells to initiate progression beyond the basal membrane.