Mucoepidermoid carcinoma of the thyroid

Abstract

Clinical and morphological features of three cases of primary mucoepidermoid carcinoma of the thyroid are described. The tumours were composed of two cell types. One of these resembled squamous epithelium and ultrastructurally showed tonofilaments and numerous desmosomes. The other cell type contained Alcian blue and mucicarmine positive mucin and, on electron microscopy, showed mucigen granules. Marked stromal fibrosis and psammoma bodies were seen in all tumours. Immunohistochemical studies showed that the tumour cells were negative for thyroglobulin. A few calcitonin-containing cells were seen in one metastatic tumour. One tumour showed, in addition to the histological features of mucoepidermoid carcinoma, anaplastic areas with obvious transition between the two histological patterns. The same thyroid also had a small thyroglobulin-positive papillary carcinoma in the opposite lobe. All tumours presented lymph node metastases. In two cases the primary tumour was confined within the thyroid capsule but that with anaplastic areas invaded surrounding structures. This patient died 13 months after diagnosis; the other patients are alive and symptomless one and 10 years since diagnosis. Mucoepidermoid carcinoma of the thyroid appears to be a clinicopathological entity that resembles papillary carcinoma in its natural history. The origin of the tumour is unclear. There is, however, some histological and immunohistological data suggesting that the tumour might be related to the ultimobranchial system although some histological features also appear to favour a common origin with papillary carcinoma.

Primary Mucoepidermoid Carcinoma and Sclerosing Mucoepidermoid Carcinoma with Eosinophilia of the Thyroid Gland: A Report of Nine Cases

“…In keeping with the hypothesis that this tumor is a follicular-derived neoplasm, one of our cases developed an anaplastic carcinoma that led to the death of the patient. In two previously reported cases (10,16), anaplastic carcinoma was also found and both of these patients died of their tumor.…”

“…The ages of the patients range from 10 to 66 years. Histologically, it bears resemblance to the lesion of the salivary glands, showing mucincontaining cysts of varying size and solid epithelial nests (10,15,20). Intracytoplasmic mucin (as stained by mucicarmine and alcian blue stains) can be found especially in tumor cells lining the cysts (10 -18).…”

“…Many authors have suggested that these tumors develop from ultimobranchial body rests/ solid cell nests (19, 26 -29), whereas some authors have reported a follicular origin (14,16,17,20). The other suggested sources include C cells, parathyroid, ectopic salivary gland, and thyroglossal duct (10,11,16).…”

Primary Sclerosing Mucoepidermoid Carcinoma with Eosinophilia of the Thyroid: Description of a Case and Review of the Literature

“…[5][6][7][8][9][10] In 1991, Chan et al Pathologically, SMECE is characterized by sclerosis, mucin, and squamous features with eosinophilic infiltrate surrounded by desmoplastic stroma. 4,[11][12][13][14][15][16][17] It is often associated with Hashimoto's thyroiditis. 1) Immunohistochemistry of most cases of SMECE described by Chan et al 1) were positive for carcinoembryonic antigen and cytokeratin.…”

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

“…A média de idade é de 40 anos, variando entre 10 a 83 anos. O prognóstico se mostra favorável na maioria dos casos, entretanto a associação com carcinoma papilífero e anaplásico pode contribuir para maior agressividade tumoral e pior prognóstico (2,6,8,10,12,13,15). No relato atual, esta associação foi encontrada e pode explicar a agressividade e a rá-pida evolução da neoplasia.…”