Imatinib mesylate neoadjuvant treatment for rectal malignant gastrointestinal stromal tumor

Figure 1 CT scan image at pelvic showing a large low-density lesion arising from the rectum.

Figure 2 Different images of the rectal tumor. A: Histopathological microphotograph of biopsy tissue showing spindle-shaped cells with obvious atypia and active mitoses (HE, × 200); B: Envision immunohistochemical stained tumor cells showing strong and diffuse positive staining for CD117 (HE, × 200); C: Macroscopic image of the resected tissue showing a submucosal tumor grayish and uniformly soft tissue texture, measuring 4 cm × 3.5 cm × 3 cm in size; D: Histological examination of the resected tissue showing no residual tumor cells, except for blood vessels and scattered lymphocytes (HE, × 200).