Journal of Biological Sciences1727-30481812-5719Asian Network for Scientific Information10.3923/jbs.2020.134.137K. SherwaniRana AkhtarKafil HaiyatSadaf QayyumAbdul 32020203Brown tumour is a non-neoplastic lesion resulting from abnormal bone metabolism in hyperparathyroidism. These are rare focal giant cell lesions that arise as a direct result of the effect of parathyroid hormone on bone tissue in some patients with hyperparathyroidism and can affect the mandible, maxilla, clavicle, ribs and pelvic bone. The term brown tumour comes from the colour of lesion, which results from the vascularity, haemorrhage and deposits of hemosiderin. The main objective of this study was to investigate the peripheral brown tumour associated with secondary hyperparathyroidism simulating a peripheral giant cell lesion of the tibia. Experiment was conducted on a 12 years old male who presented with pain and deformity in the right leg with a globular bone-expanding lesion in the mid of the tibia. Fine needle aspiration cytology of mass showed multinucleated giant cells admixed with plump to spindle shaped cells. Histological sections showed regions of discrete bone resorption with osteoclast activity, areas with newly formed bone tissue and a loose fibrillar matrix with deposits of hemosiderin and multinucleated giant cells.]]>Ahmad, R. and J.M. Hammond,200437701713Daniels, J.S.M.,200498409413Guney, E., O.G. Yigitbasi, F. Bayram, V. Ozer and Ö. Canoz,200128369372Suarez-Cunqueiro, M.M., R. Schoen, A. Kersten, J. Klisch and R. Schmelzeisen,20046210241028Okada, H., J.E. Davies and H. Yamamoto,200058233238Shang, Z.J., Z.B. Li, X.M. Chen, J.R. Li and J.M. McCoy,200361621625Düsünsel, R., E. Güney, Z. de Gündüz, M.H. Poyrazoglu, O.G. Yigitbasi and O. Kontas,200014529530Vikram, H.R., A. Petito, B.F. Bower and M.H. Goldberg,200058567569Alvarado, F., S.G. Waguespack, J.H. Campbell and T.P. Williams,20036113181323Martinez-Gavidia, E.M., J.V. Bagan, M.A. Milian-Masanet, E.L. de Miguel and A. Perez-Valles,200029447449Guimaraes, A.L.S., L. Marques-Silva, C.C. Gomes, W.H. Castro, R.A. Mesquita and R.S. Gomez,2006429193Merz, M.N., D.D. Massich, W. Marsh and D.E. Schuller,200223173176