[A Case of Rectal Cancer Diagnosed Based on Brain Metastasis and Had a Long-Term Prognosis by Radical Resections].

The patient was a 57-year-old man who visited the department of neurosurgery for headache and lightheadedness. He was admitted with a diagnosis of brain tumor based on imaging findings. Severe brain dysfunction and mild ataxia were observed, and craniotomy tumor resection was performed 5 days after admission. He was diagnosed with brain metastasis of colorectal cancer based on histopathological examination and endoscopic findings, and was therefore referred to our department. No extracranial metastases were observed, laparoscopic-assisted low anterior resection was performed 1 month after the craniotomy. The final diagnosis was rectal cancer(Ra), pT3N0M1a(BRA), Stage Ⅳa. Three months after the craniotomy, subsequent MRI examination revealed a new metastatic lesion inferior to the tumor excision cavity, and gamma knife radiosurgery was performed. However, because an increasing tendency was noted, craniotomy was performed again 7 months after the first craniotomy. Following operative treatment, follow up has been performed without adjuvant chemotherapy or prophylactic irradiation, the patient has survived without recurrence at 34 months postoperatively. Here, we report a valuable rare case of solitary brain metastasis of colorectal cancer in which prognosis could be expected by radical resections.