Melanocytic tumours of CNS

1. melanocytic schwannoma
2. melanocytomas
3. primary melanomas
4. metastatic melanomas

• middle age or later
• relatively indolent clinical behaviour
• attached to the leptomeninges or dura
• often in association with spinal nerve roots
• circumscribed masses
• spindle shaped and epithelioid cells
• abundant melanin production
• vs malignant melanoma - absence of  nuclear pleomorphism, mitosis and necrosis
• vs melanotic schwannoma - ultrastructural studies

• from melanocytes normally found in the leptomeninges
• can produce pigmented masses
• can also have diffuse leptomeningeal growth
• characteristic in childhood examples of the neurocutaneous melanosis complex
• high risk for CSF spread
• exclude cutaneous, mucosal or ocular primay

• likely to be the case in this patient
• parietal and frontal regions are the most common sites for CNS metastases
• deep seated tumour not involving the meninges would favour a metastasis
• multicentricity

• liver
• lungs
• GIT
• bone
• CNS
• anywhere

lung
• breast
• melanoma
• renal
• colorectal