Abdullah S. Shaikh, MD, Ravi Pavurala, MD, Eric Gou, MD; University of Texas Medical Branch, Galveston, TX
Introduction: Approximately 20% of patients with newly diagnosed colorectal cancer present with distant metastatic disease. The most common sites of metastases are liver, lung, peritoneum and lymph nodes. Brain metastasis from colorectal cancer is uncommon and usually associated with metachronous metastases in other organs. We describe a rare case of a 49-year-old patient presenting with headaches and left-sided weakness found to have a solitary brain metastasis from primary rectal cancer.
Methods: A 49-year-old Caucasian male with a history of tobacco and alcohol abuse presented with one month of worsening headaches, two weeks of left-hand weakness, and 30 lbs. of unintentional weight loss. MRI brain showed a 4.4 x 4.0 x 3.7 cm right frontal mass with associated 1.3 cm right to left midline shift. The patient was admitted to the neurosurgery service and underwent a right craniotomy due to initial suspicion of a high-grade glioma. However, pathology of the resected mass showed adenocarcinoma with immunohistochemical profile most consistent with colorectal primary malignancy. Review of systems revealed eight months of non-bloody diarrhea associated with fecal urgency. He did not have a family history of colorectal cancer (CRC) in any first degree relative. Carcinoembryonic antigen was elevated at 4.6 ng/mL. CT imaging of the chest, abdomen and pelvis showed ill-defined, nodular wall thickening of rectum and sigmoid colon, sub centimeter presacral and lower para-aortic lymph nodes and no other distant metastatic lesions. Flexible sigmoidoscopy demonstrated a partially obstructing rectal mass with biopsies consistent with rectal adenocarcinoma. He was referred to oncology and is awaiting systemic palliative chemotherapy with FOLFOX and bevacizumab. Discussion: Brain metastases are the most common intracranial neoplasm and typically arise from melanoma, lung, and breast cancers. Brain metastases from gastrointestinal cancers are uncommon and occur up to 0.06-4% in patients with CRC. Primary rectal cancer, young age, lung and liver metastases, and KRAS mutation are risk factors associated with brain metastases in patients with CRC. Intracranial imaging should be included in the initial workup of colorectal cancer in patients with risk factors for brain metastases.
Endoscopic view of rectum showing fungating and polypoid circumferential mass with luminal narrowing extending into anus.
MRI of Brain with and without contrast showing right lateral frontal intra-axial heterogenous enhancing mass measuring 4.4 x 4.0 x 3.7 cm with surrounding edema and right to left midline shift
Disclosures: Abdullah Shaikh indicated no relevant financial relationships. Ravi Pavurala indicated no relevant financial relationships. Eric Gou indicated no relevant financial relationships.