title: Secondary osteosarcoma arising from osteochondroma following autologous stem cell transplantation with total-body irradiation for neuroblastoma: A case report.
abstract: The present study reports the first case of malignant transformation to osteosarcoma arising from osteochondroma following childhood total-body irradiation (TBI). The association between TBI and later development of osteochondroma is well-known; however, malignant degeneration arising from radiation-induced osteochondroma is rare. The current study describes the case of a 17-year-old boy with osteosarcoma arising from osteochondroma of the left distal humerus, which developed following TBI. TBI was administered as part of a conditioning regimen received prior to autologous peripheral hematopoietic stem cell transplantation (HSCT) at the age of 6 years, following an initial diagnosis of neuroblastoma at the age of 5 years. The patient subsequently underwent preoperative chemotherapy followed by wide local excision and reconstruction with an extracorporeally irradiated autograft. Postoperative chemotherapy was administered, and the patient demonstrated no clinical or radiographic evidence of recurrence after 40 months of follow-up. To the best of our knowledge, this is only the second reported case of malignant degeneration of osteochondroma following childhood TBI, and the first reported case of transformation to osteosarcoma. The current case highlights the importance of close observation for secondary malignancies in this patient population.
authors.affiliation: Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8510, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kawashima
authors.affiliation: Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8510, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Ogose
authors.affiliation: Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8510, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Hotta
authors.affiliation: Division of Pediatrics, Department of Homeostatic Regulation and Development, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8510, Japan.
authors.forename: Chihaya
authors.initials: C
authors.lastname: Imai
authors.affiliation: Division of Pediatrics, Department of Homeostatic Regulation and Development, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8510, Japan.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Imamura
authors.affiliation: Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8510, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Endo
keywords: osteochondroma; osteosarcoma; secondary malignancy; total-body irradiation