RENAL Nephrometry Score Calculator

Quantifies anatomical characteristics of renal tumors for surgical planning and risk assessment.

R – Radius (maximum tumor diameter)

≤ 4 cm (1 point)

4-7 cm (2 points)

≥ 7 cm (3 points)

E – Exophytic/Endophytic Properties

≥ 50% exophytic (1 pt)

< 50% exophytic (2 pts)

Entirely endophytic (3 pts)

N – Nearness to Collecting System

≥ 7 mm (1 point)

4-7 mm (2 points)

≤ 4 mm (3 points)

A – Anterior/Posterior Location

Anterior (a)

Posterior (p)

Cannot determine (x)

L – Location Relative to Polar Line

Entirely above upper or below lower polar line (1 point)

Mass crosses polar line (2 points)

≥ 50% crosses polar line OR entirely between polar lines OR crosses axial midline (3 points)

Hilar Location

Tumor abuts main renal artery or vein (add suffix “h”)

Results

Total RENAL Score: —

Complexity Category: —

Select all parameters to see complete results.

Complexity	Score Range	Overall Complications	Major Complications (Clavien-Dindo ≥3)
Low	4-6	13.2%	2.6%
Moderate	7-9	22.2%	6.7%
High	10-12	41.2%	23.5%

Complication Type	Low (4-6)	Moderate (7-9)	High (10-12)
Hemorrhage requiring transfusion	2.6%	4.4%	17.6%
Urinary leak	2.6%	4.4%	11.8%
Acute kidney injury	0%	4.4%	5.9%
Reoperation	0%	2.2%	11.8%

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What is Nephrometry score?

RENAL Nephrometry Score was developed to standardize the assessment of anatomical features of renal tumor. The scoring system is based on the five most reproducible features that characterize the anatomy of a solid renal mass on imaging, commonly contrast enhanced renal mass protocol CT scans:

R: Radius-scores tumor size as maximal diameter
E: Exophytic/endophytic properties of the tumor
N: Nearness of the deepest portion of the tumor to the collecting system or renal sinus
A: Anterior (a)/posterior (p) descriptor
L: Location relative to the polar line.

How do you calculate Nephrometry score?

Each component is scored, and the total gives the Nephrometry score. This helps to stratify renal lesions into low, intermediate and high risk of complications for surgical planning.

Component	1 Point	2 Points	3 Points
R (radius, maximal diameter) (cm)	≤ 4	4-7	≥ 7
E (exophytic/endophytic)	≥ 50 % exophytic	< 50% exophytic	Completely endophytic
N (nearness to collecting system/renal sinus) (mm)	≥ 7	4-7	≤ 4
A (anterior/posterior locator)	No points given. Descriptor of “a,” “p,” or “x” assigned to describe mass location
L (location relative to polar lines)	Entirely below lower polar or above upper polar line	Mass crosses polar line	50% of mass is across polar line or mass is entirely between polar lines or mass crosses axial midline

R.E.N.A.L Nephrometry Score

How to determine location relative to polar lines for R.E.N.A.L. Nephrometry score:

Reference:

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Disclaimer: The author makes no claims of the accuracy of the information contained herein; this information is for educational purposes only and is not a substitute for clinical judgment.

This page was last updated on Mar 16, 2025 @ 3:31 pm

RENAL Nephrometry Score Calculator