Papillary thyroid carcinoma is the most common thyroid malignancy, and has an excellent prognosis, even with cervical lymph node metastasis; however, histological variants are considered relevant, which may be associated with familial adenomatous polyposis and tumor aggressiveness. Histological features, such as vascular and/or lymphatic invasion, angiogenesis, multifocality, high cellular proliferation rate, neoplastic cell dissemination, and the histological varieties, are indicative of poor prognosis, together with associated clinical factors: age, sex, and tumor size.

Ameloblastoma behavior is related to the potential of tumor cells to inhibit apoptosis and to initiate a proliferative phase. This study was performed to compare the immunoexpression of Survivin with Bcl-2, Bax, and Ki-67 and to associate them with the histopathological type of each variant of ameloblastoma. Material and Methods. Using the World Health Organization (WHO) criteria for ameloblastoma, 110 cases were selected. The cases were classified as solid/multicystic and unicystic ameloblastomas. Cellular counts of cytoplasmic immunoexpression were assessed for cytoplasmic Survivin, Bcl-2, and Bax, while the nuclear immunoexpression of Survivin and Ki-67 was assessed using label index. Results. Cytoplasmic Survivin and Bcl-2 showed higher percentages of immunoexpression in solid multicystic ameloblastomas compared to unicystic ameloblastomas (P < 0.05). Bax, Ki-67, and nuclear Survivin were expressed in higher percentages in unicystic ameloblastomas. Conclusions. Cytoplasmic Survivin and Bcl-2 immunoexpression levels were elevated in relation to Bax immunoexpression, suggesting aggressive ameloblastoma behavior, while Ki-67 and nuclear Survivin immunoexpression may be associated with the type of tumor morphology that influences cellular counts or with the greater capacity for cellular proliferation and tumor growth.

Ameloblastic fibrodentinoma (AFD) is considered a mixed odontogenic tumor that is characterized by conserved epithelial and ectomesenchymal neoplastic components. AFD is composed of long narrow cords and islands of odontogenic epithelium; the epithelial strands lie in a myxoid cell-rich ectomesenchymal tissue with stellate-shaped fibroblasts that exhibit long slender cytoplasmic extensions that resemble dental papilla. The lesions show the presence of dysplastic dentin. Although AFD is a rare entity and its very existence is not completely accepted, based on the extent of histodifferentiation, it is considered to represent a stage between ameloblastic fibroma and ameloblastic fibroodontoma. This study aimed to provide a histopathological and immunohistochemical characterization of this infrequent tumor. A large panel of antibodies including amelogenin, Ck 19, calretinin, syndecan-1, E-cadherin, MSH2, histone H3, and Ki-67 was used to illustrate the nature of the tumor.

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