The epiphyseal involvement of metaphyseal bone sarcomas in patients with fertile growth plates. A magnetic resonance assessment

The growth plate is thought to be capable of limiting tumor spread. To assess the presence and extent of epiphyseal involvement in bone tumors, the plain radiographs and the MR images of 41 patients with metaphyseal sarcoma and radiographically apparent growth plate were studied. The results were compared with surgical, microscopic and histologic findings. Histology demonstrated that in 3 patients the tumor did not reach the growth plate, in 25 the epiphysis was involved while in 13 cases the tumor reached the physis but did not spread to the epiphysis. In the latter group of patients, histology demonstrated a microinfiltration of the physis in 5 cases. Radiography and MR sensitivities were 77.2% and 100%, respectively, while specificity was 94% for both methods. Histology showed that the epiphysis was involved in 25/41 cases (61%) and the growth plate in 30/41 (73%). Our results show that the growth plate does not usually act as a barrier against tumor spread and that MRI is the diagnostic tool of choice in the assessment of epiphyseal spread in metaphyseal tumors even though it cannot detect growth plate microinfiltrations.