Figure 1.

Patient with early-stage colorectal cancer, diagnosed by colonoscopy. (A) Abdominal computed tomography detected a small mass with a diameter of ~2 cm in the front of the spleen (green arrow), but no symptoms were exhibited by the patient. (B) The surgery removed colorectal cancer and the mass in the front of the spleen at the same time. The titanium clips marked the rectal tumor (blue arrow), which was diagnosed as a highly-differentiated adenocarcinoma, with a diameter of ~0.7 cm, that had infiltrated the submucosa, but had not metastasized to the lymph nodes. The lesion in the lower-right of the image was diagnosde as GIST (red arrow), and spindle cells were observed following hematoxylin and eosin staining, with 2 mitoses per 50 high power fields. The findings of immunohistochemical analysis were CD117(+), discovered on GIST-1(+) and CD34(+), with a Ki67 index of 10%, α-SMA(−), S-100(−) and desmin(+). GIST, gastrointestinal stromal tumor; CD, cluster of differentiation.