Ewing sarcoma of the tibia mimicking fibrous dysplasia

In this study, we performed a retrospective review of children who presented with an otherwise benign-appearing lesion of the tibia, suggestive of FD, which proved to be ES after biopsy. As a result, all patients presented with a history of indolent lower extremity pain of several months of duration, without significant swelling or constitutional symptoms. Plain films revealed an otherwise benign-appearing/FD-like lesion without bone destruction and mild cortical thinning, little or no periosteal reaction. Magnetic resonance imaging revealed the intramedullary extension of the lesion without significant cortical or periosteal involvement and no soft tissue mass. Lesions were hypointense on T1-weighted imaging and hyperintense on T2-weighted imaging. All patients underwent open incisional biopsy and after cytogenetic and molecular studies, the diagnosis of ES was confirmed. We conclude that ES is a deadly malignant tumor if left untreated or if mismanaged. Although it usually presents as an aggressive-looking lesion, at times it may mimic FD and has a benign-looking appearance, making the diagnosis unlikely and challenging. Summation of these cases demonstrates that the potential reasons for misdiagnoses include a low level of suspicion, an atypical site occurrence, a benign radiographic appearance, and a lack of or insufficient histologic specimens.
Source: Journal of Pediatric Orthopaedics B - Category: Orthopaedics Tags: Leg Source Type: research