title: Malignant transformation of fibrous dysplasia: A case report.
abstract: Secondary osteosarcoma from fibrous dysplasia (FD) is very rare. The etiology of FD is linked to activating missense mutations of the guanine nucleotide-binding protein α-subunit (GNAS) gene, which encodes the stimulatory α subunit of the G protein (Gsα) and is located at chromosome 20q13. These mutations are central to the pathogenesis of FD; however, it is not known whether Gsα mutations are retained following malignant transformation in FD. In addition, to the best of our knowledge, no studies have been performed on chromosomal analysis of secondary osteosarcoma from FD. The present study presents a case of secondary osteosarcoma arising from polyostotic FD in a 72-year-old male. Chromosomal analysis showed 44, X, -Y, add(4)(p11), add(5)(p15), der(11)add(11)(p15)t(1;11)(q21;q23), add(12)(q11), -13, der(22)t(12;22)(q11;p12). Reverse transcription-polymerase chain reaction (RT-PCR) analysis demonstrated the presence of a Gsα mutation in both the primary tumor cells and secondary osteosarcoma cells. There was no alteration in this mutation in the region of malignant transformation, which suggests that this mutation may be a useful clinical marker for distinguishingde novoosteosarcoma (primary osteosarcoma) from secondary osteosarcoma arising from FD.
authors: Department of Orthopedic Surgery, Niigata Cancer Center Hospital, Niigata 951-8566, Japan.
authors: Hiroshi
authors: H
authors: Hatano
authors: Department of Orthopedic Surgery, Niigata Cancer Center Hospital, Niigata 951-8566, Japan.
authors: Tetsuro
authors: T
authors: Morita
authors: Department of Orthopedic Surgery, Niigata Cancer Center Hospital, Niigata 951-8566, Japan.
authors: Takashi
authors: T
authors: Ariizumi
authors: Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8510, Japan.
authors: Hiroyuki
authors: H
authors: Kawashima
authors: Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8510, Japan.
authors: Akira
authors: A
authors: Ogose
keywords: fibrous dysplasia; malignant transformation; mutation; secondary osteosarcoma