Are nasal polyps ever cancerous or turn cancerous?

Rarely, if ever: Common nasal polyps are usually due to allergy and do not become cancerous. It is possible for a cancer in the nasal cavity to project into the nasal lumen and meet the technical definition of a polyp, albeit very rarely.

Nasal polyps: Are usually associated with chronic inflammation of the nose caused by allergies or chronic sinusitis- they are benign. Rarely, other disease can mimic nasal polyps such as an inverting papilloma (ip). Ip is a locally aggressive tumor and although benign, can progress to a malignancy in a small percentage of cases.If polyp occurs only on one side, bleeds, painful- see your doctor for further eval.

Rarely: Papillomas in the nose look like nasal polyps and become cancerous in 5-15% of cases. Normal nasal polyps do not.