BACKGROUND: Low-grade osteosarcoma, including low-grade central osteosarcoma and parosteal osteosarcoma, is an extremely rare variant, and the diagnosis is occasionally difficult. In this article we present cases of low-grade osteosarcomas that should be reviewed by a clinical oncologist. PATIENTS AND METHODS: Nine cases of histologically diagnosed Broder grade 1 osteosarcoma were retrospectively reviewed. The pathological diagnoses included parosteal osteosarcoma, low-grade central osteosarcoma, and low-grade chondroblastic osteosarcoma in four, four, and one cases, respectively. RESULTS: Duration from initial surgical intervention including biopsy to final diagnosis as low-grade osteosarcoma was a mean of 9.4 months. The initial benign diagnoses on biopsy specimens included fibrous dysplasia in three cases, chondroblastoma in one case, and a giant cell tumor in one case. The average number of histological examinations was 1.8. Low-grade osteosarcomas are well suited for biological reconstruction: seven cases were reconstructed by frozen autografts, distraction osteogenesis, or vascularized bone grafts. CONCLUSION: Low-grade osteosarcomas can be misdiagnosed as benign lesions, especially fibrous dysplasia. If the diagnosis of a low-grade osteosarcoma is not established on the basis of radiologic findings, care should be exercised, even when a biopsy suggests a benign lesion. Low-grade osteosarcomas should be treated with wide excision, even after an intralesional excision. Biological reconstruction might be a better option for low-grade osteosarcomas.
BACKGROUND: Low-grade osteosarcoma, including low-grade central osteosarcoma and parosteal osteosarcoma, is an extremely rare variant, and the diagnosis is occasionally difficult. In this article we present cases of low-grade osteosarcomas that should be reviewed by a clinical oncologist. PATIENTS AND METHODS: Nine cases of histologically diagnosed Broder grade 1 osteosarcoma were retrospectively reviewed. The pathological diagnoses included parosteal osteosarcoma, low-grade central osteosarcoma, and low-grade chondroblastic osteosarcoma in four, four, and one cases, respectively. RESULTS: Duration from initial surgical intervention including biopsy to final diagnosis as low-grade osteosarcoma was a mean of 9.4 months. The initial benign diagnoses on biopsy specimens included fibrous dysplasia in three cases, chondroblastoma in one case, and a giant cell tumor in one case. The average number of histological examinations was 1.8. Low-grade osteosarcomas are well suited for biological reconstruction: seven cases were reconstructed by frozen autografts, distraction osteogenesis, or vascularized bone grafts. CONCLUSION: Low-grade osteosarcomas can be misdiagnosed as benign lesions, especially fibrous dysplasia. If the diagnosis of a low-grade osteosarcoma is not established on the basis of radiologic findings, care should be exercised, even when a biopsy suggests a benign lesion. Low-grade osteosarcomas should be treated with wide excision, even after an intralesional excision. Biological reconstruction might be a better option for low-grade osteosarcomas.
Authors: P Ragazzini; G Gamberi; M S Benassi; C Orlando; R Sestini; C Ferrari; L Molendini; M R Sollazzo; M Merli; G Magagnoli; F Bertoni; T Bohling; M Pazzagli; P Picci Journal: Cancer Detect Prev Date: 1999