Fig. 3

Pathological findings of the resected specimen. a In hematoxylin-eosin staining, the tumor consisted of relatively homogenous spindle cells with few mitoses (< 1%). b Both the cytoplasm and nucleus were positive in β-catenin staining. c In desmin staining, vascular smooth muscles were positive whereas tumor cells were marginally positive. d In c-kit staining, only mast cells were positive