title: Rapidly growing fibro-osseous pseudotumor of the digits mimicking extraskeletal osteosarcoma.
abstract: Fibro-osseous pseudotumor of the digits is a rare benign lesion characterized histopathologically by a fibroblastic proliferation with foci of osseous differentiation. We report a case of fibro-osseous pseudotumor of the digits with a rapidly growing lesion in a 30-year-old woman. Because of its rapid growth and aggressive histopathological appearance, this lesion can be mistaken for a malignant neoplasm such as extraskeletal or parosteal osteosarcoma, despite its benign clinical behavior. For a soft tissue mass in the digit with a clinicopathological feature of pseudomalignancy, the clinician should consider fibro-osseous pseudotumor of the digits as a possible diagnosis, thereby avoiding inappropriately aggressive surgery.
authors.affiliation: Department of Pathology, School of Medicine, Fukuoka University, Fukuoka, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Nishio
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Iwasaki
authors.forename: Osamu
authors.initials: O
authors.lastname: Soejima
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Naito
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kikuchi
mesh_terms: D000328:Adult; D001847:Bone Diseases / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D001859:Bone Neoplasms / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D005385:Fingers / Q000601:surgery; D006801:Humans; D012516:Osteosarcoma / Q000175:diagnosis*