leptomeningeal metastases
Pronunciation: lep-toh-meh-NIN-jee-uhl
Cancer spread to the pia mater and arachnoid membranes surrounding the brain and spinal cord, causing neurological dysfunction.
Full Definition
Leptomeningeal metastases represent the dissemination of cancer cells to the pia mater and arachnoid membranes that comprise the leptomeninges surrounding the central nervous system. This condition, also known as carcinomatous meningitis or neoplastic meningitis, most commonly arises from breast cancer, lung cancer, and melanoma. Diagnosis requires a combination of clinical symptoms (headache, altered mental status, cranial neuropathies), imaging findings (leptomeningeal enhancement), and cerebrospinal fluid analysis demonstrating malignant cells. Treatment is challenging and typically involves intrathecal chemotherapy, radiation therapy, and supportive care, with generally poor prognosis.
Usage
Usage note: Use specific term rather than generic 'CNS metastases' when leptomeninges are involved.
In Context
- "MRI revealed leptomeningeal metastases with enhancement along the brainstem surface." — neuroradiology report
- "The patient developed leptomeningeal metastases six months after initial lung cancer diagnosis." — oncology progress note