Table 1.
Summary of cases reported in the literature with low-grade extraskeletal osteosarcoma, including the present case1 3–9
| Reference | Age/sex | Initial diagnosis | Location | Largest diameter | Treatment | Clinical outcome and follow-up period |
|---|---|---|---|---|---|---|
| 4 | 39/M | Myositis ossificans | Right thigh | 5 cm | Surgery | Did well for initial 5 years, but finally died with metastatic disease with high-grade histological picture |
| 5 | 57/F | LG-ESOS | Right popliteal fossa | 24 cm | Surgery | Disease free, 5 years |
| 6 | 74/F | Parosteal OS | Left axillae | 15 cm | Surgery | Disease free, 2 years |
| 7 | 3/F | LG-ESOS | Right temporal lobe of the brain | Not specified | R2 resection followed by chemotherapy (MTX, D, CP) and radio-surgery for residual mass | No distant or local relapse, 18 months |
| 8 | 35/F | Myositis ossificans | Left leg | 11 cm | Surgery | Disease free, 4 years |
| 3 | 40/F | Parosteal OS | Left upper back | 9 cm | Surgery | Lost to follow-up after 2 months |
| 3 | 32/M | LG-ESOS | Right thigh, and other areas | 16 cm | Inadequate surgery and chemotherapy (MTX) | Did not respond to chemotherapy given for 8 months, lung and retroperitoneum metastasis (high-grade histology), 4 years, death |
| 1 | 62/F | Differential diagnosis of OS, leiomyosarcoma, recurrent phaeochromocytoma | Retroperitoneum | 14 cm | Surgery | Died with a widespread metastasis (high-grade histology) after 33 months |
| 9 | 30/M | Myositis ossificans | Chest | 30 cm | Chemotherapy (D, CP, I) | Loco-regional extension, death 5 years after initial symptoms and 1 year after correct diagnosis |
| Present case | 38/M | LG-ESOS | Retroperitoneum | 18 cm | Surgery and chemotherapy (CP, D) | Disease free, 3 years |
CP, cisplatin; D, doxorubicin; I, ifosfamide; LG-ESOS, low-grade extraskeletal osteosarcoma; MTX, methotrexate; OS, osteosarcoma.