Papillary urothelial neoplasm of low malignant potential (PUNLMP) is an exophytic (outward growing), (microscopically) nipple-shaped (or papillary) pre-malignant growth of the lining of the upper genitourinary tract (the urothelium), which includes the renal pelvis, ureters, urinary bladder and part of the urethra.

[citation needed] PUNLMPs are exophytic lesions that appear friable to the naked eye and when imaged during cystoscopy.

[citation needed] Histologically, they have a papillary architecture with slender fibro vascular cores and rare basal mitoses.

[citation needed] They cannot be reliably differentiated from low grade papillary urothelial carcinomas using cytology,[1] and their diagnosis (vis-a-vis low grade papillary urothelial carcinoma) has a poor inter-rater reliability.

Delayed presentation with recurrent low-grade urothelial carcinoma is an unusual entity and potential mechanism of traumatic implantation should be considered.