Anal canal gastrointestinal stromal tumors: Case report and literature review

Figure 1 Endoanal ultrasound. Posterior hipoecoid nodule, well circumscribed, between internal and external anal sphincter, with posterior enhancement and central calcification. CAM: Middle anal canal; EAI: Internal anal sphincter; EAE: External anal sphincter; SE: Subepithelium.

Figure 2 Anal canal magnetic resonance imaging. A: Coronal T2-weighted image. Anal canal left lateral wall, well circumscribed nodule, solid component. No evidence of adenopathy; B: Axial T2-weighted image.

Figure 3 Hematoxylin and eosin (× 400), eosinophlic, fusiform cells with elongated nuclei.

Figure 4 Positive immunostaining for CD117.