PGR and neoplasm: The immunoprofile of the tumor was CD99 positive (Figure 4), calretinin positive (Figure 5), inhibin positive, alpha smooth muscle actin positive, vimentin positive, estrogen receptor negative, progesterone receptor negative, keratin AE1/AE3 negative, alpha fetoprotein (AFP) negative, CD117 (KIT) negative, and placental alkaline phosphatase negative.