Primary mucoepidermoid carcinoma of the thyroid: Diagnosis by fine‐needle aspiration biopsy

Abstract

Fine-needle aspiration biopsy (FNAB) has been recognized as a safe and reliable procedure in the evaluation of thyroid nodules. We herein report a case of a low-grade mucoepidermoid carcinoma of the thyroid that was diagnosed with this technique. Examination of an intra-operative FNAB showed cohesive clusters of polygonal squamoid cells with distinct cellular borders, uniform round nuclei, distinct nucleoli, and homogeneous amphophilic to cyanophilic cytoplasm. Focal keratin "pearl" formation was apparent, along with extracellular, lightly basophilic mucin deposits mantled by squamoid cells. These cytologic features are characteristic of low-grade mucoepidermoid carcinoma, as seen in other anatomic sites. This impression was confirmed by examination of paraffin sections. Previous reports have indicated that mucoepidermoid thyroid carcinoma is an indolent, locally recurring lesion. However, in spite of low-grade histology in our case, the neoplasm presented with distant metastases to bones, pleura, and lung.

Fine Needle Aspiration Cytology of High Grade Mucoepidermoid Carcinoma of the Breast

“…[1][2][3][4][5][6][7][8][9][10] Fisher et al 15 suggested that the real frequency in the breast is higher that thought since MEC may masquerade under other diagnoses, such as atypical squamous metaplasia, in the context of infiltrating ductal carcinoma. The diagnosis of our case was initially incorrect since in the preliminary cytologic study, the tumor was thought to be a ductal carcinoma associated with atypical squamous metaplasia.…”

“…[1][2][3][4][5][6][7][8][9][10] Those locations are extremely rare; the majority have been described as isolated cases. Only 24 cases have been reported to occur in the breast; of them, just one was diagnosed by fine needle aspiration cytology (FNAC).…”

Carcinoma mucoepidermóide de tireóide: relato de caso e revisão da literatura

“…Entretanto, quanto ao CMET, não há certeza sobre a capacidade de produção de TG pelas células tumorais, nem se essas células sejam capazes de captar o radioiodo. De acordo com os casos levantados na literatura, houve positividade para TG em 41% deles, nos quais esse marcador foi utilizado na análise imunohistoquímica (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20).…”

“…Os autores que utilizaram marcadores neuroendócrinos demonstraram positividade destes marcadores na maioria dos casos (2,8,13). Os resultados com o marcador tireoglobulina (TG) foram divergentes: a maioria dos estudos mostrou negatividade para este marcador nos tumores mucoepidermóides (2,4,10,12,15,17,18,20,23). No entanto, em alguns casos, numa mesma amostra ocorreu positividade para TG nas células foliculares não envolvidas pela neoplasia e negatividade nas células realmente comprometidas (5).…”

“…CARCINOMA MUCOEPIDERMÓIDE PRIMÁRIO da tireóide (CMET) é uma neoplasia maligna muito rara, com apenas 33 casos relatados na literatura (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). A apresentação clínica inicial é de bócio uni ou multinodular atóxico, podendo haver comprometimento ganglionar ao diagnóstico.…”