View source for Papillary urothelial neoplasm of low malignant potential

{{Infobox medical condition (new)
| name            = PUNLMP (Papillary Urothelial Neoplasm of Low Malignant Potential)
| image           = Punlmp2.jpg
| caption         = [[Micrograph]] of a PUNLMP. Intermediate magnification. [[H&E stain]].
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| field           = [[Urology]], [[pathology]]
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'''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]], [[ureter]]s, [[urinary bladder]] and part of the [[urethra]].
''PUNLMP'' is pronounced ''pun''-''lump'', like the words ''pun'' and ''lump''.
As their name suggests, PUNLMPs are [[neoplasm]]s, i.e. [[molecular cloning|clonal]] [[cell (biology)|cellular]] [[mitosis|proliferation]]s, that are thought to have a low [[probability]] of developing into urothelial cancer, i.e. a [[malignancy]] such as [[bladder cancer]].
==Signs and symptoms==
PUNLMPs can lead to [[blood]] in the [[urine]] ([[hematuria]]) or may be asymptomatic.{{cn|date=April 2021}}
==Diagnosis==
[[Image:Punlmp1.jpg|thumb|right|[[Micrograph]] of a PUNLMP showing characteristic features (see text). [[H&E stain]].]]
PUNLMPs are exophytic lesions that appear friable to the naked eye and when imaged during [[cystoscopy]].
They are definitively diagnosed after removal by [[microscopy|microscopic]] examination by [[pathologist]]s.{{cn|date=April 2021}}
[[Histology|Histologically]], they have a papillary architecture with slender [[fibrous tissue|fibro]] [[vascular]] cores and rare basal [[mitosis|mitoses]].  The papillae rarely fuse and uncommonly branch.  [[Cytopathology|Cytologically]], they have uniform nuclear enlargement.{{cn|date=April 2021}}
They cannot be reliably differentiated from low grade papillary urothelial carcinomas using cytology,<ref name=pmid16697785>{{cite journal |vauthors=Jones TD, Cheng L |title=Papillary urothelial neoplasm of low malignant potential: evolving terminology and concepts |journal=J. Urol. |volume=175 |issue=6 |pages=1995–2003 |date=June 2006 |pmid=16697785 |doi=10.1016/S0022-5347(06)00267-9 }}</ref> and their diagnosis (vis-a-vis low grade papillary urothelial carcinoma) has a poor [[inter-rater reliability]].<ref name=pmid17095142>{{cite journal |vauthors=MacLennan GT, Kirkali Z, Cheng L |title=Histologic grading of noninvasive papillary urothelial neoplasms |journal=Eur. Urol. |volume=51 |issue=4 |pages=889–97; discussion 897–8 |date=April 2007 |pmid=17095142 |doi=10.1016/j.eururo.2006.10.037 }}</ref>
Pathologic grading and staging tumors are:
graded by the degree of cellular atypia (G1->G3), and
staged:{{cn|date=April 2021}}
* papilloma
* papillary tumor of low malignant potential (PTLMP)
* papillary urothelial carcinomas low grade
* papillary urothelial carcinomas high grade.
===Differential diagnosis===
[[File:Expression of p53 in urothelial neoplasms.png|thumb|[[Immunohistochemistry]] for [[p53]] can help distinguish a PUNLMP from a low grade urothelial carcinoma. Overexpression is seen in 75% of low-grade urothelial carcinomas and only 10% of PUNLMP.<ref>Image is taken from following source, with some modification by Mikael Häggström, MD:<br>- {{cite journal| author=Schallenberg S, Plage H, Hofbauer S, Furlano K, Weinberger S, Bruch PG | display-authors=etal| title=Altered p53/p16 expression is linked to urothelial carcinoma progression but largely unrelated to prognosis in muscle-invasive tumors. | journal=Acta Oncol | year= 2023 | volume=  | issue=  | pages= 1-10 | pmid=37938166 | doi=10.1080/0284186X.2023.2277344 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=37938166  | doi-access=free }} </ref><ref>Source for role in distinguishing PUNLMP from low-grade carcinoma:<br>- {{cite journal| author=Kalantari MR, Ahmadnia H| title=P53 overexpression in bladder urothelial neoplasms: new aspect of World Health Organization/International Society of Urological Pathology classification. | journal=Urol J | year= 2007 | volume= 4 | issue= 4 | pages= 230-3 | pmid=18270948 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=18270948  }} </ref>]]
* Papilloma.
* Low grade papillary urothelial carcinoma.
==Treatment==
PUNLMPs are treated like non-invasive low grade papillary urothelial carcinomas,<ref name=pmid16697785/> excision and regular follow-up cystoscopies.
There is a rare occurrence of a pelvic recurrence of a low-grade superficial TCC after cystectomy. Delayed presentation with recurrent low-grade urothelial carcinoma is an unusual entity and potential mechanism of traumatic implantation should be considered. Characteristically low-grade tumors are resistant to systemic chemotherapy and curative-intent surgical resection of the tumor should be considered.{{cn|date=April 2021}}
==References==
{{Reflist}}
{{DEFAULTSORT:Punlmp}}
[[Category:Urological neoplasia]]