PECAM1 and metastasis: Thyroid invasion occurred in 2 patients, including 1 with right zone IV lymph node metastasis.[6] Immunohistochemical spindle cells expressed vimentin, EMA, or SMA, but did not express CK, S-100, CD31, Desmin, P40, and 1 case expressed P63.[5] Epithelial components are expressed as epithelial markers.