Dendritic cell subpopulations in carcinoma ex-pleomorphic adenoma: A multicenter study.

OBJECTIVE: Carcinoma ex-pleomorphic adenoma (CEXPA) represents a malignant transformation from a recurrent or primary pleomorphic adenoma (PA), and the immune response may be essential in this process. Therefore, in this study, we aimed to identify and quantify subpopulations of dendritic cells (DCs) in CEXPA, residual PA in CEXPA (rPA), and PA. MATERIALS AND METHODS: A multicenter study was performed collecting salivary gland tumor (SGT) samples from three Oral and Maxillofacial Pathology Centers. A tissue microarray containing 41 samples of CEXPA and 22 samples of PA was included in this study and submitted to immunohistochemical reactions against CD1a, CD83, CD207, and Ki67 antibodies. RESULTS: Both PA and rPA showed a higher quantification of CD207+ and CD83+ cells when compared to CEXPA (p < 0.001 and p < 0.01, respectively). There was also a difference when comparing the cell proliferation index between PA/rPA and CEXPA using the Ki-67 marker (p = 0.043). However, there was no difference in the DC population regarding clinical parameters such as sex, anatomical location, size, and metastases (p > 0.06). CONCLUSIONS: Immunohistochemical profile of DC subpopulations and cell proliferation biomarkers in SGTs can contribute as an important tool in the differentiation of benign and malignant tumors or detection of initial areas with malignant transformation.

Maxillary Parosteal Osteosarcoma: Additional case Report and Literature Review of Surface Osteosarcomas.

Introduction: Surface osteosarcomas represent around 3-6% of all osteosarcomas, which include the parosteal (low-grade), periosteal (intermediate-grade) and high-grade surface osteosarcomas. The classical location is the femur, followed by tibia and humerus. Parosteal osteosarcoma is the most common type of surface osteosarcoma. To date, 26 cases of parosteal osteosarcoma affecting the jaws have been reported, with most cases following an evolution time of several months to years, clinically favoring a benign osseous or fibro-osseous lesion. Methods: Here, we report a 39-year-old female who was referred presenting a maxillary tumoral mass 5 years ago, clinically diagnosed as osteoma. After clinical, imaginological and histopathological analysis, a diagnosis of parosteal osteosarcoma was made. Conclusion: Thus, parosteal osteosarcoma should also be considered in the differential diagnosis of benign-appearance, bone-forming nodular lesions affecting the jaws.

Approaches to the diagnosis of secretory carcinoma of the salivary glands: a case series and review.

Secretory carcinoma (SC) is a salivary gland neoplasm included in the latest World Health Organization Classification of Head and Neck Tumours. Its morphologic and immunohistochemical characteristics resemble those of breast secretory carcinoma, and the tumors share the same fusion gene, ETV6::NTRK3. This chromosome translocation can be confirmed through reverse transcription-polymerase chain reaction or located using ETV6 fluorescent in situ hybridization. These techniques are expensive, and few laboratories can carry out molecular analysis. In addition, some of these tumors are related to non-NTRK fusion types and non-ETV6 translocation. Therefore, recognition of the typical histopathologic features of SC is the first step in considering this disease among the diagnostic hypotheses. In this case series, morphologic findings combined with immunohistochemical profiles were sufficient to make the correct diagnosis.

CTNNB1 and APC mutations in odontogenic carcinoma with dentinoid.

The purpose of the present study is to report 2 cases of odontogenic carcinoma with dentinoid, a rare low-grade odontogenic carcinoma associated with facial deformity and bone loss, and to investigate the presence of pathogenic mutations in these samples. By using a next-generation sequencing approach, we sequenced a panel of 50 oncogenes and tumor suppressor genes commonly mutated in human cancer. Microscopic features of both cases revealed solid areas of malignant odontogenic tumor with a large amount of dentinoid material. We identified pathogenic mutations in the genes CTNNB1 and APC, both of which are part of the Wnt-signaling pathway. Consistent with Wnt-signaling activation, both tumors showed strong ß-catenin accumulation in the cytoplasm and in the nuclei. The molecular profile of odontogenic carcinoma with dentinoid may help in its diagnosis, as well as in the identification of potential molecular targets for therapy in the future.

Fatty acid synthase and Ki-67 immunoexpression can be useful for the identification of malignant component in carcinoma ex-pleomorphic adenoma.

BACKGROUND: Fatty acid synthase (FASN) is the key molecule for catalyzing fatty acid synthesis and have been associated with several malignant tumors. METHODS: We analyzed the expression of FASN and Ki-67, by immunohistochemistry on 29 carcinomas ex-pleomorphic adenoma (CXPAs) and 25 pleomorphic adenomas (PAs). RESULTS: Ki-67 proliferation index and FASN expression were significantly higher in patients with CXPA than patients with PA (P < 0.001). We found intense immunoreactivity for FASN in the malignant component of CXPAs, and these malignant areas also had intense nuclear immunoreactivity for Ki-67. CONCLUSIONS: The present results suggest that overexpression of FASN in CXPAs might be associated with malignant transformation of ductal epithelial cells and/or myoepithelial cells from PA. FASN associated with Ki-67 may be useful diagnostic markers for CXPA.

High diagnostic accuracy and reproducibility of fine-needle aspiration cytology for diagnosing salivary gland tumors: cytohistologic correlation in 182 cases.

OBJECTIVE: The purpose of this study was to assess the efficacy and reproducibility of the cytologic diagnosis of salivary gland tumors (SGTs) using fine-needle aspiration cytology (FNAC). The study aimed to determine diagnostic accuracy, sensitivity, and specificity and to evaluate the extent of interobserver agreement. STUDY DESIGN: We retrospectively evaluated SGTs from the files of the Division of Pathology at the Clinics Hospital of São Paulo and Piracicaba Dental School between 2000 and 2006. RESULTS: We performed cytohistologic correlation in 182 SGTs. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were 94%, 100%, 100%, 100%, and 99%, respectively. The interobserver cytologic reproducibility showed significant statistical concordance (P < .0001). CONCLUSIONS: FNAC is an effective tool for performing a reliable preoperative diagnosis in SGTs and shows high diagnostic accuracy and consistent interobserver reproducibility. Further FNAC studies analyzing large samples of malignant SGTs and reactive salivary lesions are needed to confirm their accuracy.