Unusual brain metastasis from colon cancer

Abstract

Background: Brain metastases due to colorectal cancer correspond to 3-5% of all brain metastases. The prognostic factors are based on age, functional status, and single metastasis. Its management is multidisciplinary, with poor prognosis despite the management.

Case description: A case of a 64-year-old male presented with symptoms of headache, disorientation, and nausea. The enhanced magnetic resonance image showed a mass in the right frontal horn of the lateral ventricle, contrast enhancing, with irregular borders, but defined, without restriction in diffusion-weighted images, associated with obstructive hydrocephalus. The investigations in search of a primary neoplasm were negative. A ventricular endoscopic approach was performed, with total resection of the lesion. Four months later, he developed a bowel obstruction with surgical management to control the primary, followed by chemotherapy and radiotherapy, with a current survival longer than 1 year.

Conclusion: Brain metastases due to colorectal cancer are rare, and usually, when diagnosed, there are already pulmonary and hepatic metastases. Multidisciplinary management is recommended, where surgical management can be included in selected cases with controlled systemic disease, good functional condition, and single metastasis.

Keywords: Brain cancer; Brain metastasis; Cerebral ventricle neoplasms; Colon cancer; Neoplasms unknown primary.

Figure 1:

Contrast-enhanced brain magnetic resonance imaging preoperative. (a) Contrast-enhanced T1 image in the axial section that shows a mass in the right frontal horn (arrow), which seems to obstruct the ipsilateral foramen of Monro. (b) Contrast-enhanced T1 image in axial view, 5 mm above image a, which shows the same tumor (thin arrow); furthermore, it shows ventricular dilation (empty arrow) with transependymal edema (thick arrow). (c) Contrast-enhanced T1 image in sagittal view shows the tumor in the right foramen of Monro (arrow). (d) Contrast-enhanced T1 image in coronal view, which evidences the tumor in the lower edge of the right frontal horn (arrow) close to the ipsilateral foramen of Monro. (e) T2 image shows a tumor in the right frontal horn, isointense (arrow thin), associated with ventricular dilation (empty arrow) and transependymal edema (thick arrow). (f) Diffusion-weighted image shows no restriction of the tumor of the right frontal horn (arrow).

Figure 2:

(a) Intraoperative image, showing a brownish gray tumor (thin arrow), hypervascularized (thick arrow), by endoscopic view using a handmade endoport (empty arrow). (b) Intraoperative endoscopic image with a handmade endoport (empty arrow), where the same tumor is shown (thick arrow) with defined borders (thin arrow) that allow distinguishing the tumor from the medial wall of the right frontal horn of the lateral ventricle. (c) Intraoperative image with partial resection tumor with moderate bleeding (thin arrow), where the resection continued with aspiration (thick arrow). (d) Nonenhanced brain computed tomography (CT) on the 1^st postoperative day, absence of tumor, with little bleeding in the surgical field is shown (thin arrow), also the distal end of the external ventricular catheter is seen (empty arrow). (e) Enhanced brain CT on the 5^th postoperative day, without external ventricular shunt, where there is no evidence of contrast-enhancing lesions, with little bleeding in the surgical field (arrow).

Figure 3:

Microscopic description: (a) Proliferation of malignant glandular formations (green arrow) immersed in a mucinous matrix. Note the presence of choroid plexuses with benign characteristics (red arrows). Hematoxylin and eosin (HE) ×4. (b) Malignant glandular epithelium, with mucinous cytoplasm. HE ×10. (c) Malignant cells were positive for CK20. HE ×4. (d) They were also positive for β catenin. HE ×10.

Figure 4:

Contrast-enhanced brain magnetic resonance imaging in the 4^th postoperative month. (a) Contrast-enhanced T1 image in axial view shows a new metastasis, nodular, contrast-enhancing in the inferior border of the IV ventricle (arrow). (b) Contrast-enhanced T1 image in sagittal view shows the metastasis in the IV ventricle (arrow); in addition, the lesion recurrence in the right front horn is seen (empty arrow). (c) Contrast-enhanced T1 image in axial view shows the recurrence of the contrast-enhancing right frontal horn tumor (arrow), without associated ventricular dilation. (d) T2 image shows a recurrence of the right frontal horn tumor, isointense (thin arrow), that seems to invade the cavum vergae (empty arrow) and not the former surgical field. (e) Diffusion-weighted image shows no signal restriction (arrow).