Fig. 4From: Sphincter-saving resection by cluneal arched skin incision for a gastrointestinal stromal tumor (GIST) of the lower rectum: a case report a, b The resected tumor was 3.5 × 3.5 × 2.5 cm in size. The rubbery-hard tumor with widespread central necrosis was completely capsulized. c Microscopic examination (hematoxylin-eosin staining, original magnification: ×400) revealed a formation of spindle-shaped cells. d Immunohistochemical staining of the tumor cells for c-kit revealed strong positive findingsBack to article page