title: Mucoepidermoid carcinoma arising in Warthin's tumor of the parotid gland.
abstract: Malignant transformation of Warthin's tumor is extremely rare, although it is the second most common benign tumor of the parotid gland. We describe our experience of mucoepidermoid carcinoma arising in Warthin's tumor of the parotid gland in a 64-year-old man. He had a swelling in the left parotid-masseteric region. The removed tumor was well encapsulated and histopathologically comprised Warthin's tumor and low-grade mucoepidermoid carcinoma. The mucoepidermoid carcinoma infiltrated lymphoid stroma of the Warthin's tumor, but capsular invasion is not found. Considering the clinical course and physical examination, the lesion was diagnosed as mucoepidermoid carcinoma arising in Warthin's tumor because its features filled the criteria of malignant transformation of Warthin's tumor. There has been no recurrence or distant metastasis for 19 months. Histological change from Warthin's tumor to mucoepidermoid carcinoma may be implicated in squamous or goblet cell metaplasia of epithelial cells. It is considered that the neoplastic cells of Warthin's tumor acquire malignant genotypes simultaneously with this dual differentiation.
authors.affiliation: Department of Developmental and Reconstructive Medicine, Nagasaki, Japan. d400014h@stcc.nagasaki-u.ac.jp
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Yamada
authors.forename: Takemitsu
authors.initials: T
authors.lastname: Matsuo
authors.forename: Shuichi
authors.initials: S
authors.lastname: Fujita
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Suyama
authors.forename: Akira
authors.initials: A
authors.lastname: Yamaguchi
authors.forename: Akio
authors.initials: A
authors.lastname: Mizuno
mesh_terms: D000235:Adenolymphoma / Q000473:pathology* / Q000601:surgery; D018277:Carcinoma, Mucoepidermoid / Q000473:pathology* / Q000601:surgery; D018572:Disease-Free Survival; D006801:Humans; D008297:Male; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000473:pathology*; D010307:Parotid Neoplasms / Q000473:pathology* / Q000601:surgery; D014057:Tomography, X-Ray Computed