Fig. 5

Rectal stromal tumor, immunohistochemistry immunostains. a Cell block showing syncytial tissue fragment with mixed spindle and epithelioid cells. Hematoxylin and eosin. b A strong positive staining with CD117/c-kit. c Strong positive reaction with CD34. d Negative reaction with desmin. e Negative reaction with S-100 protein. f Weak nuclear staining for Ki-67 in tumor cells