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Salivary Gland Tumors
Published in Dongyou Liu, Tumors and Cancers, 2017
Risk factors for salivary gland tumors include exposure to ionizing radiation (e.g., previous radiotherapy for head and neck neoplasms), rubber product manufacturing, asbestos mining, plumbing, and woodworking. Genetic alterations have been also observed in MEC (chromosome translocation t[11;19][q14–21;p12–13], MECT1-MAML2); ACC and hyalinizing clear cell carcinoma (MYB-NFIB and EWSR1-ATF1 gene fusions, respectively); acinic cell carcinoma, cystadenocarcinoma, and adenocarcinoma NOS (ETV6-NTRK3); and salivary duct carcinoma (6q and 17p/17q mutations, chromosome 7 polysomy, 12q amplification, 9p LOH, methylation of MGMT, DAPK, and RASSF1) [2,4].
Pulmonary mucoepidermoid carcinoma: diagnosis and treatment
Published in Expert Review of Respiratory Medicine, 2018
From the diagnostic point of view of daily practice, the diagnosis of pulmonary MEC may represent a challenge in a small biopsy. In such cases, the tumor can be easily misinterpreted for a squamous cell carcinoma if the biopsy shows only the epidermoid component and the presence of mucoid secreting cells is not present or is inconspicuous. Immunohistochemical stains in this setting may not be of help as both tumors may share similar immunohistochemical profile. However, by far, the most difficult separation may be with two unusual tumors of the lung – mucous gland adenoma and hyalinizing clear cell carcinoma. Bronchial mucous gland adenomas are unusual tumors that share similar histopathological features with MEC [48]. Even though some believe that in cases of mucous gland adenoma, the tumor remains circumscribed within the bronchial wall, such an assessment can be made only after complete resection of the tumor and not in the evaluation of a small biopsy. In cases of hyalinizing clear cell carcinoma of the bronchus [8,9], the tumor by definition will show the presence of prominent clear cell proliferation with extensive hyalinization. However, in small biopsies, the presence of clear cells and hyalinization may also be seen in cases of bronchial MEC. In such cases, the evaluation of MAML2 may be of aid in arriving at a more specific diagnosis.
A case of nasopharyngeal clear cell carcinoma diagnosed by molecular analysis
Published in Acta Oto-Laryngologica Case Reports, 2018
Makiko Hara, Naoki Otsuki, Shungaku Yanagisawa, Norio Kokan, Hisami Fujio, Hitomi Shinomiya, Naruhiko Morita, Shigeru Hara, Hiroshi Inagaki, Ken-Ichi Nibu
Histopathologically, CCC was first described in 1994 by Milchgrub et al. as a unique entity made up of clear cells that form nests and cords in hyalinized stroma. Initially, CCC was called as hyalinizing clear cell carcinoma (HCCC) but was renamed as CCC in the new edition of WHO classification of Head and Neck in 2017. Since CCC has a wide differential diagnosis including other clear-cell containing tumors, such as epithelial–myoepithelial carcinoma, mucoepidermoid carcinoma (MEC), and myoepithelial carcinoma, it is very difficult to distinguish CCC from other clear-cell containing tumors based on the histopathological examination [1]. However, recently, consistent expression of Ewing sarcoma breakpoint region 1-activating transcription factor 1 (EWSR-ATF1) fusion protein has been reported in CCC. The EWSR1 rearrangement by fluorescence in situ hybridization (FISH) presented in 18 of 22 (82%) cases of CCC [2] suggested its potential role in the pathological diagnosis of CCC.