leptomeningeal melanomatosis
Diffuse involvement of the leptomeninges by melanoma cells, either primary or metastatic.
Full Definition
Leptomeningeal melanomatosis refers to the diffuse involvement of the pia and arachnoid mater by melanoma cells. This can occur as metastatic spread from systemic melanoma or arise primarily from melanocytes normally present in the leptomeninges. The condition presents as thickening and darkening of the meninges with melanin-laden cells infiltrating the subarachnoid space. Diagnosis is confirmed by cerebrospinal fluid cytology showing melanoma cells and imaging demonstrating leptomeningeal enhancement. The prognosis is generally poor, and the condition can cause hydrocephalus, cranial nerve palsies, and seizures due to cortical irritation.
Usage
Usage note: Specify whether primary or secondary; note melanin pigmentation.
In Context
- "CSF cytology confirmed leptomeningeal melanomatosis with numerous pigmented malignant cells." — Cerebrospinal fluid analysis report
- "The autopsy revealed extensive leptomeningeal melanomatosis with black discoloration of the meninges." — Neuropathology autopsy report