View source for Papillary renal neoplasm with reverse polarity

{{ Infobox diagnosis
| Name       = {{PAGENAME}}
| Image      = Papillary renal neoplasm with reverse polarity - alt -- high mag.jpg
| Width      =
| Caption    = Papillary renal neoplasm with reverse polarity. [[H&E stain]].
| Synonyms   =
| Micro      = papillary structures, eosinophilic cytoplasm, reverse polarity of nuclei (nuclei at luminal aspect of cell), low nuclear grade
| Subtypes   =
| LMDDx      = eosinophilic [[papillary renal cell carcinoma]], other [[renal tumours with eosinophilic cytoplasm]]
| Stains     =
| IHC        = GATA3 +ve, PAX-8 +ve, CK7 +ve, CD10 +ve, CD117 -ve
| EM         =
| Molecular  = [[KRAS]] mutations
| IF         =
| Gross      =
| Grossing   = [[partial nephrectomy]], [[radical nephrectomy]]
| Staging    =
| Site       = [[kidney]] - see ''[[kidney tumours]]''
| Assdx      =
| Syndromes  =
| Clinicalhx =
| Signs      =
| Symptoms   =
| Prevalence = rare
| Bloodwork  =
| Rads       =
| Endoscopy  =
| Prognosis  = indolent - based on limited data
| Other      =
| ClinDDx    = other [[kidney tumours]]
| Tx         =
}}
'''Papillary renal neoplasm with reverse polarity''' is a rare [[renal tumour]] and an evolving entity.<ref name=pmid31135486>{{cite journal |authors=Al-Obaidy KI, Eble JN, Cheng L, Williamson SR, Sakr WA, Gupta N, Idrees MT, Grignon DJ |title=Papillary Renal Neoplasm With Reverse Polarity: A Morphologic, Immunohistochemical, and Molecular Study |journal=Am J Surg Pathol |volume=43 |issue=8 |pages=1099–1111 |date=August 2019 |pmid=31135486 |doi=10.1097/PAS.0000000000001288 |url=}}</ref> It has a distinctive morphology that matches the name.

==General==
*Evolving entity.
*Thought to be distinct from ''eosinophilic [[papillary renal cell carcinoma]]''.<ref name=pmid38456605>{{cite journal |authors=Castillo VF, Trpkov K, Van der Kwast T, Rotondo F, Hamdani M, Saleeb R |title=Papillary renal neoplasm with reverse polarity is biologically and clinically distinct from eosinophilic papillary renal cell carcinoma |journal=Pathol Int |volume=74 |issue=4 |pages=222–226 |date=April 2024 |pmid=38456605 |doi=10.1111/pin.13417 |url=}}</ref><ref name=pmid37797754>{{cite journal |authors=Kim B, Lee S, Moon KC |title=Papillary renal neoplasm with reverse polarity: a clinicopathologic study of 43 cases with a focus on the expression of KRAS signaling pathway downstream effectors |journal=Hum Pathol |volume=142 |issue= |pages=1–6 |date=December 2023 |pmid=37797754 |doi=10.1016/j.humpath.2023.09.011 |url=}}</ref>
*Early data suggests an indolent behaviour.<ref name=pmid31135486>{{cite journal |authors=Al-Obaidy KI, Eble JN, Cheng L, Williamson SR, Sakr WA, Gupta N, Idrees MT, Grignon DJ |title=Papillary Renal Neoplasm With Reverse Polarity: A Morphologic, Immunohistochemical, and Molecular Study |journal=Am J Surg Pathol |volume=43 |issue=8 |pages=1099–1111 |date=August 2019 |pmid=31135486 |doi=10.1097/PAS.0000000000001288 |url=}}</ref>

==Micro==
Features:<ref name=pmid31135486/>
*Branching papillae with:
**Thin fibrovascular cores.
**Cuboidal to columnar lining cells with granular eosinophilic cytoplasm.
***May have occasional cytoplasmic clearing.
**Smooth luminal borders.
**Reverse polarized nuclei (luminal nuclei; nuclei closer to lumen than basement membrane).
**Nucleoli absent or small.

DDx:
*Eosinophilic [[papillary renal cell carcinoma]] - considered distinct from this entity.
*[[Renal tumours with eosinophilic cytoplasm]].

===Images===
<gallery>
Image: Papillary renal neoplasm with reverse polarity -- very low mag.jpg | PRNRP - very low mag.
Image: Papillary renal neoplasm with reverse polarity -- low mag.jpg | PRNRP - low mag.
Image: Papillary renal neoplasm with reverse polarity - alt -- low mag.jpg | PRNRP - low mag.
Image: Papillary renal neoplasm with reverse polarity -- intermed mag.jpg | PRNRP - intermed. mag.
Image: Papillary renal neoplasm with reverse polarity -- high mag.jpg | PRNRP - high mag.
Image: Papillary renal neoplasm with reverse polarity -- very high mag.jpg | PRNRP - very high mag.
</gallery>

==IHC==
Features:<ref name=pmid31135486/>
*CK7 +ve.
*CD10 +ve (all cases).
*GATA3 +ve (all cases).
*Vimentin -ve (all cases).
*CD117 -ve.
*AE1/AE3 +ve.
*EMA +ve.
*L1CAM +ve.

==Molecular==
*[[KRAS]] mutations.<ref name=pmid37797754/>

==Sign out==
<pre>
A. Right Kidney, Tumour, Partial Nephrectomy:
	- Papillary renal neoplasm with reverse polarity, clear of margin, see comment.

Comment:
The tumour has a papillary architecture, eosinophilic cytoplasm, low nuclear grade, and reversed nuclear polarity.

It stains as follows:
POSITIVE: PAX8 (moderate, diffuse), CK7 (strong, diffuse), AE1/AE3 (strong, diffuse), GATA3 (moderate, diffuse), AMACR (moderate, diffuse).
NEGATIVE: vimentin (stroma), CD117, CD10.

The findings are in keeping with papillary renal neoplasm with reverse polarity (PRNRP). PRNRP is thought to be distinct from papillary RCC.[1][2]  Limited data suggests PRNRP has an indolent behaviour.[3] Follow-up is recommended. 

1. Pathol Int. 2024 Apr;74(4):222-226. doi: 10.1111/pin.13417. https://pubmed.ncbi.nlm.nih.gov/38456605/
2. Hum Pathol. 2023 Dec:142:1-6. doi: 10.1016/j.humpath.2023.09.011. https://pubmed.ncbi.nlm.nih.gov/37797754/
3. Am J Surg Pathol. 2019 Aug;43(8):1099-1111. doi: 10.1097/PAS.0000000000001288. https://pubmed.ncbi.nlm.nih.gov/31135486/
</pre>

==See also==
*[[Renal tumours with eosinophilic cytoplasm]].

==References==
{{Reflist|2}}

[[Category:Diagnosis]]
[[Category:Kidney tumours]]