title: Collagenous fibroma (desmoplastic fibroblastoma) presenting as a parotid mass.
abstract: We describe the case of a 50-year-old man who was found to have a painless, slow-growing parotid mass of 10 months duration. At surgery, a well-delimited, lobulated 4x5-cm tumor was located on the deep lobe of the left parotid gland, adhering to the parotid sheath and masseteric fascia. Follow-up 6 years later has shown no evidence of recurrence. Cardinal morphologic features included multiple nodules of sparsely distributed stellate-or spindle-shaped fibroblasts within a collagenous or myxocollagenous stroma. Fascial involvement and entrapment of salivary gland were focally identified at the edges. Tumor cells were diffusely positive for vimentin with faint focal staining for alpha-smooth muscle actin. These findings satisfied the diagnostic criteria for collagenous fibroma (desmoplastic fibroblastoma). Ours represents the first report of this tumor type mimicking a parotid tumor.
authors.affiliation: Department of Oral Surgery, Saitama Medical Center, Saitama Medical School, Kawagoe, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Ide
authors.forename: T
authors.initials: T
authors.lastname: Shimoyama
authors.forename: N
authors.initials: N
authors.lastname: Horie
authors.forename: H
authors.initials: H
authors.lastname: Tanaka
mesh_terms: D018220:Fibroma, Desmoplastic / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D010306:Parotid Gland / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D010307:Parotid Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D009626:Terminology as Topic