Conjunctival melanoma

Conjunctival melanoma is a rare cancerous disease arising from melanocytes. It can develop de novo (i.e., 'out of the blue') or from a pre-existing naevus (i.e., 'mole') or from primary acquired melanosis (PAM).

When the melanoma is confined to the conjunctival epithelium, it is termed 'melanoma in situ' and when it spread deeply it is called 'invasive melanoma'.


Melanoma in situ

Melanoma in situ has the appearance of flat, brown conjunctival discolouration. This is also termed 'PAM with atypia' or 'C-MIN with atypia'.


Invasive melanoma

Invasive melanoma can be nodular or diffuse, unifocal or multifocal (i.e., single or multiple), pigmented or amelanotic and with or without superficial spread.


Without timely treatment, invasive conjunctival melanoma can spread deeply into the orbit, sinuses and the brain. It can also seed around the conjunctival surface and down the nasolacrimal duct (i.e., tear duct) into the nose. Metastatic spread can occur to the regional lymph nodes (i.e., 'glands') in the neck and more widely to other parts of the body with fatal consequences.