: tending to become malignant : precancerousa premalignant conditionOne advantage to colonoscopy is that possible cancerous lesions can be biopsied, and premalignant polyps can be removed during the same procedure.— Jane E. Brody, The New York Times, 13 May 1993A skin condition called actinic keratosis is often a premalignant precursor of squamous cell carcinoma …— Simeon Margolis et al., The Johns Hopkins White Papers, 1996