Malignant myopericytoma originating from the colon: A case report

Figure 1 Computed tomography imaging before and after the first surgery. A: Axial view of the tumor prior to surgery; B: Coronal view of the tumor prior to surgery; C: Gross specimen of surgically excised neoplastic lesion. The arrow indicates the margin of the liver and the tumor surrounding the liver; D: The arrow shows the adhesions between the tumor and the colon; E: Axial view after surgery; F: Coronal view after surgery.

Figure 2 Immunostaining results of the first surgery. A: The left half is tumor tissue and the right half is normal liver tissue. The tumor cells did not significantly invade the normal liver tissue. The arrow indicates a thickened but intact liver capsule (magnification power: 10 ×); B: Tumor cells in a concentric pattern around the blood vessels (magnification power: 100 ×); C: Abnormal mitotic figures appearing in the tumor cells (magnification power: 200 ×); D: Areas of necrosis within the tumor (magnification power: 100 ×); E: Diffuse smooth muscle actin expression in tumor cells (magnification power: 100 ×).

Figure 3 Imaging and immunohistochemical analysis before and after the second operation. A: Axial computed tomography view of the tumor prior to surgery; B: Coronal view of the tumor prior to surgery; C: Gross specimen of tumor tissue. The arrows show the mucosal layer of the colon; D: Axial view after surgery; E: Coronal view after surgery; F: Tumor cells in a concentric pattern around the blood vessels (magnification power: 100 ×); G: Abnormal mitotic figures in the tumor cells (magnification power: 200 ×); H: Hematoxylin and eosin staining revealed tumor giant cells (magnification power: 200 ×); I: Smooth muscle actin was diffusely expressed in tumor cells (magnification power: 100 ×).

Figure 4 First surveillance enhanced abdominal computer tomography scan. A and B: Axial view of the tumor in the arterial phase; C and D: Axial view of the tumor in the venous phase.