Thrombomodulin, calretinin and c-kit (CD117) expression in cardiac myxoma

Abstract

The immunohistochemica l profil e of cardiac myxoma has been debated. The tumor is thought to be de ri ve d fr om multipo te nti a l undiffe re ntiated mesenchymal cells. A consistent marker fo r this tumor has not bee n fo und . In this arti cle an immunohistoc hemi ca l stu dy of 23 ca rdi ac myxo mas was accomplished. This stud y comprised th e immunoreactivit y of the tumors fo r thrombomodulin, calretinin and and c-kit (COIl 7). To the best of our knowledge, th ro mb omodulin and c-kit have no t bee n tested in cardi ac myxoma. Ca lretinin expression has been recentl y demonstrated in cardiac myxoma, although this finding has not been yet validated. Surface lining ce lls, tumor vascular endothelium, cells around the vascular slits and stromal ce lls embedd ed in the myxoid matri x we re assessed independently. All tumors showed reactivity fo r thromb omodulin in th e surface ce lls and in th e end oth elium of neopl asti c vesse ls. 82.6% of ca rdi ac myxomas ex pressed th rombomodulin in the stromal cells and 69.6 % o f the tum o rs we re reac ti ve in th e pe ri vascul ar cells. 73.9% of cardiac myxomas expressed ca lretinin in th e stromal cells and in the peri vascul ar ce lls. All myxo mas we re nega ti ve fo r c- kit. Thrombomodulin and ca lretinin may be impo rtant diagnosti c aids for ca rdiac myxoma. Ca rdiac myxoma ce lls do no t exp ress e mbr yo ni c/fe tal e ndo th e li a l antigens.