Is there a relationship between plaque psoriasis and malignant melanoma? how often do they appear together?

Psoriasis: It is not related to melanoma, but they can both occur in one individual coincidentally.

Very rare.: There is a higher incidence of non-melaoma skin cancer in patients with psoriasis but melanoma has only occasionally been seen in psoriatic plaques. Though, if you have concerns about any areas, arrange an appointment with your dermatologist for an evaluation and possible biopsy of the site.