Rectal cancer diagnosed after resection of isolated brain metastasis

Brain metastasis of colorectal cancer is infrequent, and isolated brain metastases are more infrequent. Thus, when neurological symptoms, such as paralysis or disturbance of consciousness appear, there is a high probability that the cancer has spread to other organs.

Here, we present a 64-year-old man with a progressive headache, decreased motivation, and aphasia who was diagnosed with a brain tumor in the left frontal region. He underwent a craniotomy, and the brain tumor was diagnosed as adenocarcinoma. We performed a colonoscopy and diagnosed rectal cancer without other distant metastases. After whole-brain radiotherapy (WBRT), low anterior resection for primary rectal tumor was performed using a robotic system. The patient was discharged in good condition and received postoperative adjuvant therapy for rectal cancer. He showed no signs of recurrence after 1 year of follow-up.

We described a rare case of rectal cancer that was diagnosed after resection of isolated brain metastasis. A good prognosis was achieved with surgery and WBRT.