Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 23 3-4 1981 12 15 91 99 B. Aalami-Harandi 2015 09 28 A case of g iant cell tumor of t he vertebra simulat ing vert ebra plana was reported . t he d i agnos i s o f t he vertebra plana should not be confirmed by t he history of the patient and radiologica l manifestation alone . it can onlybe confirmed by biopsy . Bone l esions of the spine i s one of the most di fficul t problems t o diagnosis and t r eat . Spinal tumors a r e either primary or metastatic . Ilos t bone tumors of the spine i n t he first two decade of l i f e are primary and benign;where as a majority of the bone lesions in old people ar e me tast at1,c and rna I 1' 9n ant . 5- 11 The rnaI1' 9~ant Lee Ss 1i 0ns 0f t h e Sp1' - ne can wi t hout very great risk be excl uded f r om diagnostic considerati on in chi ldren and adoles cence (She r r a r d . 1969) 12 . From 34 casps of bone l esions of the spine and the pelvis i n the f irst two decade of l i f e, reported by Thommes on and 1 3 , Paulsen (1967) ni ne were histiochtosis X, two anevr ysma l bone cyst,nine Ewi ng sar coma , two reticul um cell sar c ~ma. None were g i ant cel l tumor . Giant cell tumor of the spine is r a re; mo s t of t he report ed cases were in t he sacrum. J affe (1958) 17repor t ed only two c ases of giant cell t umo r, one of which o c c ur r e d in the por t e d s a c r um.Of the 218 cases of the g i an t ce l l tumor re6 by Goldenbe rg and Carnpbell( 1970) there were 13 cases of g i ant c e l l tumor o f the ver t ebra , one in the cervical r e g i o n , o ne in the l umbar spi ne , and e l e ven in t he sacrum. Of '08 giant ce l l t umors studied by Coley( 1960)4 ,one was i n the lumba r ver t ebra and one in the s a c rum. al In a r e view of 413 tumors i nc l uding t he spine(Cohen et 3 1964) tr.ere were sixteen cases o f g i ant c e l l tumor ,one  n the c e r vica l spine , one in the l umbar r e gion and f ourte61 n the sacrum. I n thi s a r t i c l e we are going to report a case of giant cel l t umor of the s i xth thor a ci c vertebra, r adiologically simul ating vert ebra plana . https://acta.tums.ac.ir/index.php/acta/article/view/152 https://acta.tums.ac.ir/index.php/acta/article/download/152/148