CD99 and neoplasm: The viable tumor cells showed a strong membranous stains for CD99 (Figure 2(c)), focal membranous and cytoplasm stain for CD56 (Figure 2(d)), a cytoplasm dot pattern for synapthophysin (Figure 2(e)), and focal cytoplasm and membranous stain for PGP9.5, BCL2, and vimentin.