[Immunohistochemistry in the diagnosis of sarcomas].

Immunohistochemistry (IHC) is essential in the diagnosis of soft tissue tumor and must rely on good quality technic. Among useful antibodies, it is important to distinguish those with a poor specificity required in order to establish the broad lineage, from those with high specificity, which may lead straightforward towards the entity. Diagnostically useful antibodies such as myogenin, ALK1 and DOG1 have been recently completed by MUC4 and STAT6 which show good sensitivity and specificity in the diagnosis of low-grade fibromyxoid sarcoma and solitary fibrous tumor respectively. ERG is also an interesting antibody. However, it is not completely specific of vascular tumors. Moreover, available material is often limited because of the increase of microbiopsy specimens. Therefore, it is mandatory to optimize this precious tissue by using these new antibodies, especially because molecular technics are increasingly performed in addition to IHC.