Spontaneous malignant transformation of fibrous dysplasia.
OBJECTIVE
To evaluate the clinical and radiological findings in diagnosing spontaneous malignant transformation of fibrous dysplasia.


METHODS
Fifteen cases of sarcomatous transformation proved by operation and pathological examinations were found in a group of 356 patients with fibrous dysplasia, and their radiological manifestations were retrospectively studied. The 15 cases included 8 osteosarcomas, 5 fibrosarcomas and 2 chondrosarcomas. All the 15 patients were known to have long-standing fibrous dysplasia, but no radiation therapy was ever received. Eleven patients had polyostotic fibrous dysplasia and 4 had monostotic type.


RESULTS
Malignant transformation most frequently occurs in the cystic expansive lesion of the long tubular bone. Pains, swelling and late appearance of a bony mass are the main clinical manifestations. The early radiological features of sarcomatous transformation in fibrous dysplasia are moth-eaten or cystic areas of osteolysis located in the involved bone. The cortical destruction and gradual formation of a soft tissue mass that contains tumor-bone are highly suspicious of osteosarcomatous transformation, while ring-like and spotty calcification in the tumor matrix is indicative of chondrosarcoma. Fibrosarcoma usually shows simple osteolytic destruction.


CONCLUSIONS
According to the clinical radiological findings, patients of sarcomatous transformation can be detected in the early stage. These radiological findings may be used as a clue for differentiating various kinds of sarcomatous transformation.
Xu
D
D
Affiliated Hospital, Qingdao Medical College.
Luan
H
H
Zhan
A
A
Feng
W
W
Sun
X
X
Meng
F
F
D000328:Adult; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D002471:Cell Transformation, Neoplastic; D005260:Female; D005354:Fibrosarcoma / Q000000981:diagnostic imaging / Q000473:pathology; D005358:Fibrous Dysplasia, Monostotic / Q000473:pathology*; D005359:Fibrous Dysplasia, Polyostotic / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012516:Osteosarcoma / Q000000981:diagnostic imaging / Q000473:pathology*; D011859:Radiography; D012189:Retrospective Studies