TFE3 and neoplasm: The tumor cells showed patchy immunoreactivity for HMB-45 in a cytoplasmic and membranous pattern (Figure 2A), patchy moderate immunoreactivity for progesterone receptor (Figure 2B), diffuse nuclear staining for TFE3 (Figure 2C) and patchy but strong, membranous positivity with C-kit/CD117 (Figure 2D).