PGR and neoplasm: Immunohistochemical staining revealed the resected tissues to be positive for h-caldesmon, α-SMA, desmin, estrogen receptor and progesterone receptor (PR) (Fig. 2C–H), and negative for cluster of differentiation (CD)117, discovered on gastrointestinal stromal tumor-1, CD34, neuron-specific enolase and S-100, with a Ki-67 labeling index of 1%.