title: Osteosarcoma arising from desmoplastic fibroma treated 16 years earlier: a case report.
abstract: We present a rare case of malignant transformation of desmoplastic fibroma in a 37-year-old man. In 1984 we performed curettage and bone grafting for a bone tumor of the left distal femur. Histologically, we obtained a final diagnosis of desmoplastic fibroma. After this treatment, the patient had no particular symptoms but felt tension in the left knee in 2000 and consulted our department. We performed tumor curettage and bone grafting although malignant findings were recognized by imaging. The last pathology diagnosis was an osteosarcoma (in view of the formation of an osteoid). We performed caffeine-assisted chemotherapy and an additional wide excision. In the literature, two reports of a high-grade sarcoma developing in a desmoplastic fibroma have appeared. It is sometimes difficult to distinguish desmoplastic fibroma from low-grade fibrosarcoma or intraosseous-type osteosarcoma, although the radiographic findings and aspects of the resected specimen in 1984 were typical of a desmoplastic fibroma. Moreover, from a clinical standpoint, because the recurrence came 16 years after the initial operation, and lung metastasis was not seen, it is difficult to believe this case was malignant originally. This extremely rare lesion is believed to be a desmoplastic fibroma transformed to osteosarcoma.
authors.affiliation: Department of Orthopaedics Surgery, Kanazawa University Graduate School of Medical Science, 13-1 Takara-machi, Kanazawa 920-8641, Japan.
authors.forename: Koutarou
authors.initials: K
authors.lastname: Takazawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tsuchiya
authors.forename: Norio
authors.initials: N
authors.lastname: Yamamoto
authors.forename: Akitaka
authors.initials: A
authors.lastname: Nonomura
authors.forename: Masayuki
authors.initials: M
authors.lastname: Suzuki
authors.forename: Junichi
authors.initials: J
authors.lastname: Taki
authors.forename: Katsuro
authors.initials: K
authors.lastname: Tomita
mesh_terms: D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000473:pathology* / Q000601:surgery; D016025:Bone Transplantation / Q000379:methods; D003131:Combined Modality Therapy; D003475:Curettage / Q000379:methods; D005269:Femur / Q000473:pathology / Q000601:surgery; D018220:Fibroma, Desmoplastic / Q000473:pathology* / Q000601:surgery; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D019637:Orthopedic Procedures / Q000379:methods; D012516:Osteosarcoma / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy*; D011230:Precancerous Conditions / Q000473:pathology*; D011877:Radionuclide Imaging; D018570:Risk Assessment; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome