Leptomeningeal metastasis from colon cancer: a case report and review of literature.

BACKGROUND: Leptomeningeal metastasis from colorectal cancer (LM-CRC) is a rare condition characterized by poor outcomes and no established standard of care. CASE DESCRIPTION: We report a 60-year-old female patient who presented with constipation and abdominal pain. Eight months prior, she had been diagnosed with poorly differentiated adenocarcinoma of the sigmoid colon with focal signet-ring cell features, proficient mismatch repair, and a KRAS mutation. She had received treatment with FOLFOX/FOLFIRI ± bevacizumab. Five days before admission, she developed headache and vomiting. Contrast-enhanced brain MRI suggested leptomeningeal metastasis, which was confirmed by lumbar puncture cytology. Owing to progressive symptom deterioration, the patient did not receive any antitumor therapy timely and died two weeks after symptom onset. In this review, we summarize 29 cases of LM-CRC, aiming to characterize the pathology, symptoms, diagnosis, and survival data of LM-CRC in order to enhance clinicians' awareness of this rare disease. CONCLUSION: The incidence of LM-CRC is low and the prognosis is extremely poor; active anti-tumor therapy may prolong patient survival.