title: Oncocytic mucoepidermoid carcinoma of the parotid gland with CRTC1-MAML2 fusion transcript: report of a case with review of literature.
abstract: Oncocytic mucoepidermoid carcinoma is a very rare variant of mucoepidermoid carcinoma, composed predominantly of oncocytic cells. Most previously reported cases described the difficulty in histologic differentiation from other oncocytic tumors. Here we report a case of oncocytic mucoepidermoid carcinoma of parotid gland diagnosed by the detection of CRTC1-MAML2 fusion. A 53-year-old man had a left superficial parotidectomy conducted for 3-cm-sized mass. The resected tumor was composed almost exclusively of oncocytic tumor cells. With detailed histologic evaluation, scarce vacuolated tumor cells, suggestive of mucous cell of mucoepidermoid carcinoma, and one focus of tumor embolism in a vein were found, suggesting the possibility of oncocytic mucoepidermoid carcinoma. Immunohistochemically, oncocytic cells were diffusely positive for p63. Reverse transcriptase polymerase chain reaction and direct sequencing revealed CRTC1-MAML2 translocation of this tumor. To our knowledge, this report describes the first case of oncocytic mucoepidermoid carcinoma confirmed with CRTC1-MAML2 fusion. Identification of this fusion gene may help in distinguishing oncocytic mucoepidermoid carcinoma from its mimics.
authors.affiliation: Department of Otorhinolaryngology, School of Medicine, Juntendo University, Motomach Bldg. 3F, Hongo 1-1-19, Bunkyo-ku, Tokyo, Japan 113-0033.
authors.forename: Mitsuhisa
authors.initials: M
authors.lastname: Fujimaki
authors.forename: Yuki
authors.initials: Y
authors.lastname: Fukumura
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Saito
authors.forename: Keiko
authors.initials: K
authors.lastname: Mitani
authors.forename: Shiro
authors.initials: S
authors.lastname: Uchida
authors.forename: Junkichi
authors.initials: J
authors.lastname: Yokoyama
authors.forename: Takashi
authors.initials: T
authors.lastname: Yao
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Ikeda
mesh_terms: D018277:Carcinoma, Mucoepidermoid / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D003937:Diagnosis, Differential; D005500:Follow-Up Studies; D050939:Gene Fusion; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D008875:Middle Aged; D009687:Nuclear Proteins / Q000235:genetics*; D024862:Oxyphil Cells / Q000473:pathology; D016612:Paraffin Embedding; D010306:Parotid Gland / Q000473:pathology / Q000601:surgery; D012333:RNA, Messenger / Q000235:genetics; D012468:Salivary Gland Neoplasms / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D017422:Sequence Analysis, DNA; D015534:Trans-Activators; D014157:Transcription Factors / Q000235:genetics*; D014178:Translocation, Genetic / Q000235:genetics; D016896:Treatment Outcome
chemical_list: C081876:CKAP4 protein, human; C500984:CRTC1 protein, human; D004268:DNA-Binding Proteins; C471297:MAML2 protein, human; D008565:Membrane Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D015534:Trans-Activators; D014157:Transcription Factors