Difference between revisions of "Breast cancer grading"
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***Calculation: 1.52 mm<sup>2</sup> (sampling area) / 0.2376 mm<sup>2</sup> (area / FOV ) = 6.40 FsOV. | ***Calculation: 1.52 mm<sup>2</sup> (sampling area) / 0.2376 mm<sup>2</sup> (area / FOV ) = 6.40 FsOV. | ||
*'''RANT''': Sampling 10 fields, where the field of view (FOV) is 0.152 mm<sup>2</sup>, is ''not'' the same as sampling ten fields, where the FOV is 0.312 mm | *'''RANT''': Sampling 10 fields, where the field of view (FOV) is 0.152 mm<sup>2</sup>, is ''not'' the same as sampling ten fields, where the FOV is 0.312 mm<sup>2</sup>. It surpring that Elston & Ellis ignore the fact that "10 HPFs" on different microscopes represent different sample areas and that they do ''not'' standardize the sampling area. | ||
==Calculating Nottingham score== | ==Calculating Nottingham score== | ||
Revision as of 22:48, 10 March 2016
Breast cancer grading is useful prognosticator. It is done routinely on all invasive breast cancers.
The most common is the Nottingham system, also known as Scarff-Bloom-Richardson.
Nottingham system
Nottingham is based on:
- Nuclear grade.
- Small, regular (1.5-2x RBC dia.) = 1.
- Moderated variability = 2.
- Marked variation (>2.5x RBC dia.) = 3.
- Tubule formation.
- Majority of tumour - tubules >75% = 1.
- Moderate - 10% to 75% = 2.
- Minimal <10% = 3.
- Mitotic rate.
- 0-5 mitosis/10 HPF (1.52 mm^2 --or-- 0.0152 mm^2 * 10) = 1.
- 6-10 mitosis/10 HPF (1.52 mm^2) = 2.
- >11 mitosis/10 HPF (1.52 mm^2) = 3.
Mnemonic: TMN = tubule formation, mitotic rate, nuclear grade.
Notes:
Note about mitosis counting
- One really ought to adjust for the size of the field of view.
- Most of modern microscopes have an eye piece diameter of 22 mm. Therefore, the field diameter at 40x is approximately 22 mm / 40x ~= 0.55 mm and the field of view is pi/4*(0.55 mm)2 = 0.2376 mm2.
- Thus, on a typical modern microscope (with a FOV of 0.2376 mm2) one should sample 6 or 7 fields of view (FsOV).
- Calculation: 1.52 mm2 (sampling area) / 0.2376 mm2 (area / FOV ) = 6.40 FsOV.
- Thus, on a typical modern microscope (with a FOV of 0.2376 mm2) one should sample 6 or 7 fields of view (FsOV).
- RANT: Sampling 10 fields, where the field of view (FOV) is 0.152 mm2, is not the same as sampling ten fields, where the FOV is 0.312 mm2. It surpring that Elston & Ellis ignore the fact that "10 HPFs" on different microscopes represent different sample areas and that they do not standardize the sampling area.
Calculating Nottingham score
- Grade I = 3-5 points.
- Grade II = 6-7 points.
- Grade III = 8-9 points.
Notes:
- Most tumours are grade II.
- The mitotic score is most often 1/3.
- The nuclear score is rarely 1/3 -- even in the tubular subtype.[3]
See also
References
- ↑ Elston CW, Ellis IO (September 2002). "Pathological prognostic factors in breast cancer. I. The value of histological grade in breast cancer: experience from a large study with long-term follow-up. C. W. Elston & I. O. Ellis. Histopathology 1991; 19; 403-410". Histopathology 41 (3A): 151–2, discussion 152–3. PMID 12405945.
- ↑ Elston CW, Ellis IO (November 1991). "Pathological prognostic factors in breast cancer. I. The value of histological grade in breast cancer: experience from a large study with long-term follow-up". Histopathology 19 (5): 403–10. PMID 1757079.
- ↑ MUA. 20 January 2009.