Fig. 4

The epithelioid or rhabdoid tumor cells showed strongly and diffusely immunoreactivity for S100 (A, × 200) and HMB-45 (C, × 200). However, the spindle tumor components were scatteredly positive for S100 (B, × 200) and negative for HMB-45 (D, × 200). a-SMA was negative in the epithelioid or rhabdoid neoplastic cells (E, × 200) and diffusely positive in the spindle neoplastic cells (F, × 200). Desmin was focally positive in the epithelioid or rhabdoid neoplastic cells (G, × 400), and partially diffuse positivity in the spindle-shaped tumor cells (H, × 200). H-caldesmon showed focal reactivity in the epithelioid or rhabdoid neoplastic cells (I, × 200) and diffuse reactivity in the spindle neoplastic cells (J, × 200). MyoD1 was negative in all neoplastic cells (K and L, × 200)