title: Bizarre parosteal osteochondromatous proliferation (Nora's lesion) of the sesamoid: a case report.
abstract: We report the a case of Nora's lesion (Bizarre Parosteal Osteochondromatous Proliferation) of the sesamoid. A 32-year-old woman presented with a painless, enlarging mass of two years duration on the plantar aspect of the first metatarsophalangeal joint of the left foot. Radiographs, Computerized Tomographs and Magnetic Resonance images, initially suggested a parosteal osteosarcoma arising from the tibial sesamoid. The mass was excised, and a histological diagnosis of Bizarre Parosteal Osteochondromatous Proliferation of bone (Nora's lesion) was made. The aggressive growth of this lesion may suggest a neoplasm clinically. Histological features, however, are those of a reactive lesion.
authors.affiliation: Cappagh Orthopaedic Hospital, Finglas, Dublin, Ireland.
authors.forename: J A
authors.initials: JA
authors.lastname: Harty
authors.forename: P
authors.initials: P
authors.lastname: Kelly
authors.forename: D
authors.initials: D
authors.lastname: Niall
authors.forename: J C
authors.initials: JC
authors.lastname: O'Keane
authors.forename: M M
authors.initials: MM
authors.lastname: Stephens
mesh_terms: D000328:Adult; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D018216:Osteochondromatosis / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D010521:Periosteum / Q000473:pathology*; D012716:Sesamoid Bones / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome