title: Primary nasopharyngeal mucoepidermoid carcinoma in Japanese patients: two case reports with histochemical and immunohistochemical analysis and a review of the literature.
abstract: Mucoepidermoid carcinoma is a common neoplasm of the salivary glands. Salivary gland-type neoplasms are very rare in the nasopharynx, and there are only few reports on mucoepidermoid carcinoma of the nasopharynx. Two additional cases of mucoepidermoid carcinoma arising from the nasopharynx are reported here. Case 1: the patient was a 57-year-old Japanese woman who had bloody sputum. Case 2: the patient was a 51-year-old Japanese woman who underwent resection of a nasopharyngeal tumor. Histologically, both tumors were also low-grade mucoepidermoid carcinomas with clear cells. Histochemically, the gland-like nests and mucous cells were positive for mucin staining. Immunohistochemically, the lesions were positive for cytokeratins (CKs), p63, and MUC1, but negative for alpha-smooth muscle actin and EBER mRNA. The Ki-67 labeling indices of the two tumors were 10.4% and 4.3%, respectively. The two present cases and a review of the English literature indicate that salivary gland-type neoplasms arising from the nasopahrynx are extremely rare. The prognosis of salivary gland-type carcinomas of the nasopharynx is still unknown.
authors.affiliation: Pathology Division, Shizuoka Cancer Center Hospital, 1007 Shimonagakubo, Nagaizumi-cho, Sunto-gun, Shizuoka, 411-8777, Japan. k.kusafuka@scchr.jp
authors.forename: Kimihide
authors.initials: K
authors.lastname: Kusafuka
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Takizawa
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Iida
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Ebihara
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Onitsuka
authors.forename: Toru
authors.initials: T
authors.lastname: Kameya
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D018277:Carcinoma, Mucoepidermoid / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D019394:Ki-67 Antigen / Q000032:analysis; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen