leptomeningeal enhancement
Pronunciation: lep-toh-men-IN-jee-al
Abnormal contrast uptake in the thin membranes covering the brain and spinal cord, often indicating tumor spread.
Full Definition
Leptomeningeal enhancement refers to abnormal contrast accumulation within the pia mater and arachnoid mater, the thin membranes that directly cover the brain and spinal cord surfaces. In oncologic radiology, this finding often indicates leptomeningeal metastases (carcinomatosis), where cancer cells spread through the cerebrospinal fluid pathways. Primary brain tumors, metastatic disease from breast, lung, or melanoma, and hematologic malignancies can cause this pattern. The enhancement may appear as smooth, nodular, or thick irregular patterns along brain surfaces, within sulci, or around the spinal cord. Early detection requires high-quality post-contrast imaging and careful inspection of all CSF spaces.
Usage
Usage note: Distinguish from pachymeningeal (dural) enhancement; requires high-quality post-contrast imaging for detection.
In Context
- "Subtle leptomeningeal enhancement in the posterior fossa suggested CSF dissemination." — Brain MRI with contrast report
- "The pattern of leptomeningeal enhancement was consistent with metastatic breast cancer." — Neuro-oncology imaging interpretation