Telangiectatic osteosarcoma is a rare and special variant of osteogenic sarcoma with distinct radiologic, gross and microscopic features. This tumor is predominantly lytic, destructive tumor without sclerosis on roentgenogram, and is soft and cystic on gross examination. Histologically aneurysmally dilated spaces lined or traversed by stromal cells producing osteoid are noted. This report concerns a case of telangiectatic osteosarcoma occurring in a 7 years old boy. He presented with pathologic fracture of the right distal tibia, followed by a purely lytic lesion on X-ray examination. This lesion recurred five times during a span of one year. Microscopic features of the biopsy specimen was difficult to differentiate from aneurysmal bone cyst because of prominant blood-filled cyst formation. It was finally identified as osteosarcoma from the below-knee amputation specimen through the close examination for anaplastic osteoid-producing stromal cells in the septa that separate the blood cysts.
Aneurysm/complications/diagnosis ; Child ; Diagnosis, Differential ; Humans ; Male ; Neoplasm Recurrence, Local ; Osteosarcoma/complications/*pathology ; Tibia

BACKGROUNDRecent studies have suggested that the presence of a pathological fracture does not impact on oncologic outcomes and the feasibility of limb salvage surgery (LSS) in appropriately selected patients when combined with neoadjuvant chemotherapy. These have largely been single institutional studies with limited numbers. The Eastern Asian Musculoskeletal Oncology Group reviewed the data from three large volume Asian orthopedic oncology centers to determine whether the presence of a pathologic fracture affected outcomes in osteosarcoma patients.

METHODSA retrospective review of the data was conducted. Ninety-five cases of nonmetastatic extremity osteosarcoma with a pathological fracture and 887 cases without fracture treated during the same period were compared.

RESULTSIn the fracture group, the LSS rate was 62.1%, and the rate of amputation was 37.9%. In the nonfracture group, the LSS rate was 74.7%, and the amputation was 25.3%. In patients with a pathologic fracture, the rate of local recurrence for LSS and amputation groups was 8.5% and 2.8%, respectively. In this group, the 5-year survival in the LSS group was 66% as against. 46.8% in the amputation group.

CONCLUSIONSOur study suggests that surgically treated patients with pathologic fractures in osteosarcoma have adequate local control and do not have a poorer outcome compared to patients without a fracture. Though osteosarcoma with a pathologic fracture is not a contraindication for limb salvage, appropriate case selection is important when deciding local control options to ensure adequate oncologic clearance.

Adolescent ; Adult ; Aged ; Bone Neoplasms ; complications ; surgery ; Child ; Child, Preschool ; Extremities ; pathology ; surgery ; Female ; Fractures, Spontaneous ; etiology ; surgery ; Humans ; Limb Salvage ; Male ; Middle Aged ; Neoplasm Recurrence, Local ; complications ; surgery ; Osteosarcoma ; complications ; surgery ; Retrospective Studies ; Young Adult

It has been well known that the survivors of retinoblastoma are prone to have osteosarcoma. But the secondary tumor usually occurs in bilateral, hereditary type of retinoblastoma. We report one case of osteosarcoma in a survivor of unilateral, sporadic retinoblastoma. A fourteen year old male presented with a painfully swollen distal forearm of 2 month duration. He had enucleated his left eye 10 years ago due to retinoblastoma with no other adjuvant therapy. We managed him with our conventional protocol and identified deletion of Rb gene from his pathological specimen by using the PCR-RFLP method. This result is unusual for unilateral nonhereditable retinoblastoma and may suggest gene level change even in sporadic cases. And Rb gene study may be helpful for unilateral, sporadic retinoblastoma patient in detecting the possibility of late osteosarcoma.
Adolescent ; Base Sequence ; Case Report ; DNA Primers ; *Gene Deletion ; *Genes, Retinoblastoma ; Human ; Magnetic Resonance Imaging ; Male ; Molecular Sequence Data ; Osteosarcoma/complications/*genetics/pathology ; Retinoblastoma/complications/*genetics/pathology ; Support, Non-U.S. Gov't ; Survivors

Any medical diagnosis should take a multimodal approach, especially those involving tumour-like conditions, as entities that mimic neoplasms have overlapping features and may present detrimental outcomes if they are underdiagnosed. These case reports present diagnostic pitfalls resulting from overdependence on a single diagnostic parameter for three musculoskeletal neoplasm mimics: brown tumour (BT) that was mistaken for giant cell tumour (GCT), methicillin-resistant Staphylococcus aureus osteomyelitis mistaken for osteosarcoma and a pseudoaneurysm mistaken for a soft tissue sarcoma. Literature reviews revealed five reports of BT simulating GCT, four reports of osteomyelitis mimicking osteosarcoma and five reports of a pseudoaneurysm imitating a soft tissue sarcoma. Our findings highlight the therapeutic dilemmas that arise with musculoskeletal mimics, as well as the importance of thorough investigation to distinguish mimickers from true neoplasms.
Adult ; Aneurysm, False ; diagnosis ; Biopsy ; Bone Diseases ; diagnosis ; Bone Diseases, Metabolic ; diagnosis ; Bone Neoplasms ; diagnosis ; Cell Proliferation ; Diagnosis, Differential ; Diagnostic Errors ; prevention & control ; Female ; Giant Cell Tumors ; diagnosis ; Humans ; Hyperparathyroidism ; complications ; Leukocytosis ; diagnosis ; Male ; Methicillin-Resistant Staphylococcus aureus ; Middle Aged ; Neoplasms ; diagnosis ; microbiology ; Osteomyelitis ; diagnosis ; microbiology ; Osteosarcoma ; diagnosis ; Sarcoma ; diagnosis ; Soft Tissue Neoplasms ; diagnosis ; Tibia ; pathology