Benign retroperitoneal schwannoma presenting as colitis: A case report

Figure 1 Contrast-enhanced CT scan of the abdomen showing a diffuse infiltration around the rectum and the sigmoid colon, and thickening of their walls.

Figure 2 Well-demarcated, homogeneous mass measuring 60×50 mm in close proximity to the left iliac artery, lumbar vertebrae and psoas muscle, on contrast-enhanced CT scanning.

Figure 3 Coronal T₁-weighted MR image using gadolinium, showing a solid mass with the same features as seen with CT scanning.

Figure 4 Perioperative examination of the mass revealed a solid, greyish, ovoid tumor with a smooth capsule and a homogeneous yellow core.

Figure 5 Antoni A area on the right (well-organised spindle cells in a palisade pattern) and Antoni B area (less cellular, loose pleomorphic cells) on the left (HE, × 200).