title: Protuberant fibro-osseous lesions of the temporal bone: two additional case reports.
abstract: The most commonly encountered fibro-osseous lesions of the skull bone are fibrous dysplasia and ossifying fibroma. Two cases of a unique "protuberant fibro-osseous lesion of the temporal bone" were first described by Selesnick and colleagues in 1999, and 2 further cases were reported in 2010 under the name "Bullough lesion". We recently found 2 new cases of this rare entity. Two Korean female patients aged 70 and 54 years presented with slow growing postauricular masses without pain or tenderness for 6 and 7 years, respectively. Computed tomography revealed a 2.9 cm calcified mass in the temporal bone of the first patient, and a 5.5 cm enhancing mass with internal cartilaginous matrix in the temporal bone of the second patient. Intramedullary or intracranial extension was not found in either case, and en bloc removals were performed. Microscopically, multiple round to oval osseous islands were scattered throughout the bland fibrous stroma in both cases. The osseous islands varied in size and were lamellar or woven, without osteoblastic rimming, and surrounded by fibroblastic bands. Neither patient has shown evidence of postoperative recurrence for 18 months. The location, histology, and clinical course of these 2 cases were identical to the 4 cases previously reported, although age and sex varied. The lesions were tested for the R201H mutation in the GNAS gene, which is present in fibrous dysplasia. No mutations were found, suggesting a different genetic background for these lesions.
authors.affiliation: Departments of *Pathology ‡Radiology §Neuro-surgery †Asan Center for Cancer Genome Discovery, ASAN Institute for Life Sciences, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Miji
authors.initials: M
authors.lastname: Lee
authors.forename: Joon Seon
authors.initials: JS
authors.lastname: Song
authors.forename: Sung-Min
authors.initials: SM
authors.lastname: Chun
authors.forename: Jeong Hyun
authors.initials: JH
authors.lastname: Lee
authors.forename: Suk Ho
authors.initials: SH
authors.lastname: Hong
authors.forename: Kyung-Ja
authors.initials: KJ
authors.lastname: Cho
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics; D002864:Chromogranins; D004252:DNA Mutational Analysis; D005260:Female; D018214:Fibroma, Ossifying / Q000737:chemistry / Q000235:genetics / Q000473:pathology / Q000601:surgery; D005357:Fibrous Dysplasia of Bone / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D009154:Mutation; D012888:Skull Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology / Q000601:surgery; D013701:Temporal Bone / Q000737:chemistry / Q000473:pathology / Q000601:surgery; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D047368:Tumor Burden
chemical_list: D014408:Biomarkers, Tumor; D002864:Chromogranins; C406732:GNAS protein, human; D019205:GTP-Binding Protein alpha Subunits, Gs