RESUMEN
O carcinoma mucoepidermóide é um tipo de neoplasia encontrada geralmente nas glândulas salivares, mamas, pâncreas e trato digestivo. O acometimento primário da glândula tireóide é muito raro, apenas 33 casos na literatura. Embora a maioria dos casos de carcinoma mucoepidermóide de tireóide (CMET) tenha evolução favorável, o caso clínico relatado descreve uma paciente com tumor agressivo e, a partir deste relato, é apresentada revisão da literatura quanto aos aspectos clínico, histopatológico, imunohistoquímico e origem histogenética dessa neoplasia.
The mucoepidermoid carcinoma is a neoplasia that usually occurs at salivary glands, breast, pancreas and gastrointestinal tract. The primary occurrence on thyroid gland is rare and only 33 cases were previously published. Although the majority of cases of mucoepidermoid carcinoma of the thyroid (MECT) show a benign evolution, this paper describes a patient with an aggressive tumor. A literature review over clinical, histopathological, imunohistochemical features and histogenetic origin was discussed.
Asunto(s)
Humanos , Femenino , Persona de Mediana Edad , Carcinoma Mucoepidermoide/patología , Carcinoma Papilar/secundario , Neoplasias de la Tiroides/patología , Calcitonina/análisis , Carcinoma Mucoepidermoide , Carcinoma Mucoepidermoide/ultraestructura , Mucinas/metabolismo , Recurrencia Local de Neoplasia/patología , Pronóstico , Tiroidectomía , Glándula Tiroides/patología , Neoplasias de la Tiroides , Neoplasias de la Tiroides/ultraestructura , Imagen de Cuerpo EnteroRESUMEN
The lymphoepithelial cyst (LEC) rarely occurs in the thyroid gland. The LEC has been thought to be related to developmental rest, namely solid cell nest, which is derived from ultimobranchial body. We report a case of lymphoepithial cyst in a 34- year-old woman clinically diagnosed with Hashimoto's thyroiditis. The cyst was located in mid to lower portion of the left lobe. It was a single unilocular cyst, which for the most part was lined with squamous epithelium, and at certain foci with ciliated columnar epithelium. The cyst wall showed a dense lymphocytic infiltration, numerous lymphoid follicles with germinal centers and admixed thyroid follicles. This morphology is similar to the branchial cleft cyst, with the exception of the thyroid follicles in the cyst wall. Near the cyst were several solid epidermoid cell nests. Immunohistochemical stain of this cyst-lining epithelium and solid cell nests showed CEA positivity. In view of the similarity in histomorphology and CEA positivity to branchial cleft cyst of the lateral neck, the LEC of the thyroid could also have been of branchial origin. However, the admixed thyroid follicles in the cyst wall suggests that the LEC of the thyroid gland might have derived from another branchial cleft as a ultimobranchial body, because it has the potential for thyroid follicular differentiation.