Site, variant and stage: different information
Melanoma arises from melanocytes, cells found mainly in the skin but also in other tissues. Not every melanoma is therefore a primary skin tumour. The eye, certain mucosal surfaces and, very rarely, meningeal structures can be sites of origin. Identifying the site matters because biology, investigations and treatment may differ.
This section organises special forms by anatomical site. Rare variants of melanoma mainly covers microscopic descriptions and uncommon clinical settings. The pathways connect: a mucosal location and an unusual cellular appearance can coexist. Stage answers a different question: how far the disease has spread.
Eye melanoma: the uveal pathway
Eye melanoma includes different conditions. Uveal melanoma arises in the iris, ciliary body or choroid, whereas conjunctival melanoma is distinct and does not automatically follow the same pathway. The uvea is the eye’s pigmented vascular layer; the choroid is its posterior portion.
The eye melanoma page introduces symptoms, investigations and treatment. It leads to dedicated pages on iris melanoma, ciliary body melanoma and choroidal melanoma. Diagnosis requires expertise in ocular oncology; an external photograph cannot exclude an internal lesion.
Nervous system: primary or metastatic?
When melanoma affects the brain or meninges, the first distinction is between metastasis from another site and an exceptionally rare primary central nervous system melanocytic tumour. They are not synonyms. Establishing the origin, MRI and tissue assessment when indicated guide care.
The dedicated page also distinguishes neurocutaneous melanocytosis, a congenital condition that is not automatically melanoma. Neurological symptoms need medical assessment; sudden deficits or seizures require urgent care.
Mucosal disease and links to rare forms
Primary mucosal melanoma involves sites including the sinonasal and oral regions, anorectal area and genital mucosa. This is a site-based category rather than one histological form. Its detailed page remains available within the rare-forms pathway and is linked here to make it easier to find.
For comparison with skin melanomas, see common types of melanoma. Do not apply a survival figure or treatment from a different site to uveal or mucosal melanoma; the evidence must fit the individual situation.
Sources and update
Editorial revision: 17 October 2026. This information does not replace medical assessment. For very rare variants, some evidence comes from small series or case reports.