title: Bilateral metachronous periosteal osteosarcoma.
abstract: The first case of bilateral metachronous periosteal osteosarcoma (OS) is reported. A 14-year-old white boy presented with a 1-month history of pain and swelling in his right thigh. Periosteal OS was diagnosed on a basis of the radiologic and pathologic findings. Treatment was with local resection and total hip replacement after a short course of high-dose methotrexate; multi-agent chemotherapy was continued postoperatively for 3 months. He remained well for 3 years. He then represented with a mass in the left femur that had been slowly growing for about 1 year. Radiologic and biopsy studies showed periosteal OS. Full investigations showed no evidence of metastatic disease. Treatment consisted of local resection without chemotherapy. He remained well for 6 months after the second excision until developing multiple pulmonary metastases. All further therapy was refused. The question as to whether the second tumor was a new primary lesion or a metastasis is discussed, together with possible differential diagnoses.
authors.forename: A J
authors.initials: AJ
authors.lastname: Howat
authors.forename: D R
authors.initials: DR
authors.lastname: Dickens
authors.forename: D W
authors.initials: DW
authors.lastname: Boldt
authors.forename: K D
authors.initials: KD
authors.lastname: Waters
authors.forename: P E
authors.initials: PE
authors.lastname: Campbell
mesh_terms: D000293:Adolescent; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D003131:Combined Modality Therapy; D003937:Diagnosis, Differential; D005266:Femoral Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy; D006622:Hip Prosthesis; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D008297:Male; D009362:Neoplasm Metastasis; D009378:Neoplasms, Multiple Primary; D012516:Osteosarcoma / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy; D010521:Periosteum / Q000000981:diagnostic imaging / Q000473:pathology*; D014057:Tomography, X-Ray Computed