MYOG and neoplasm: In both cases, the tumor cells were nonreactive to AE1/AE3 (Dako; Clone AE1 + AE3; 1:200 dilution), cytokeratin 8/18 (Santa Cruz Biotechnology; Clone NCL-5D3; 1:100 dilution), CD117 (Dako; polyclonal; 1:100 dilution), calponin (Santa Cruz Biotechnology; Clone CALP; 1:200 dilution), S100 (Dako; polyclonal; 1:500 dilution), CD21 (Dako; Clone 1 F8; 1:25 dilution), HMB45 (Dako; 1:50 dilution), myogenin (Dako; Clone F5D; 1:50 dilution), and Myf4 (Novocastra; Clone LO26; 1:500 dilution).