Becky is right on as usual!!!! This is what is known as the Bloom Richardson Score in the medical world....this may explain it.
Bloom-Richardson Grade for Breast Cancer
Beginning with breast cancer cases diagnosed January 1, 1996, the Bloom-Richardson grading system may be used.
Synonyms include: Modified Bloom-Richardson, Scarff-Bloom-Richardson, SBR Grading, BR Grading, Elston-Ellis modification of Bloom-Richardson grading system. This grading scheme is based on three morphologic features as follows:
- <LI class=kadov-p-CSingleSpaced>degree of tumor tubule formation
<LI class=kadov-p-CSingleSpaced>tumor mitotic acitivity
- nuclear pleomorphism of tumor cells (nuclear grade)
Seven possible scores are condensed into three Bloom-Richardson grades. The three grades then translate into well-differentiated (BR low grade), moderately differentiated (BR intermediate grade) and poorly differentiated (BR high grade).
Tumor tubule formation
Score
>75% of tumor cells arranged in tubules
1
>10% and <75%
2
<10%
3
Number of mitoses
(low power scanning (X100), find most mitotically tumor area, proceed to high power (x400)
<10 mitoses in 10 high-power fields
1
>10 and <20 mitoses
2
>20 mitoses per 10 high power fields
3
Nuclear pleomorphism (nuclear grade)
Cell nuclei are uniform in size and shape, relatively small, have dispersed chromatin patterns, and are without prominent nucleoli
1
Cell nuclei are somewhat pleomorphic, have nucleoli, and are intermediate size
2
Cell nuclei are relatively large, have prominent nucleoli or multiple nucleoli, coarse chromatin patterns, and vary in size and shape
3
To obtain the final Bloom-Richardson score, add score from tubule formation plus number of mitoses score, plus score from nuclear pleomorphism. The combined score converts to the following BR grade:
Bloom-Richardson combined scores
Differentiation/BR Grade
ICD-O-3 6th digit
3, 4, 5
Well-differentiated (BR low grade)
1
6, 7
Moderately differentiated (BR intermediate grade)
2
8, 9
Poorly differentiated (BR high grade)
3
There are coding rules and conventions to be used to code breast cancer cases. Use grade or differentiation information from the breast histology in the following order:
- <LI class=kadov-p-CSingleSpaced>Bloom-Richardson scores 3-9
<LI class=kadov-p-CSingleSpaced>Bloom-Richardson grade (low, intermediate, high)
<LI class=kadov-p-CSingleSpaced>Nuclear grade
<LI class=kadov-p-CSingleSpaced>Terminology (well diff, mod diff…)
- Histologic grade (grade I, grade ii…)
Caution : In this grading system, the terms low, intermediate, and high are codes 1, 2, and 3 respectively. This is an exception to the usual rule for all other grading systems which code "low", "intermediate", and "high" as 2, 3, and 4 respectively. In the Bloom-Richardson system, if grades 1, 2, and 3 are specified, these should be coded 1, 2, and 3 respectively.
Bloom-Richardson scores
Bloom-Richardson scores
Nuclear Grade
Terminology
Histologic Grade
Code
3- 5 points
Low Grade
1/3, 1/2
Well Differentiated
(BR low grade)
1
6, 7 points
Intermediate Grade
2/3
Moderately differentiated
(BR intermediate grade)
2
8, 9 points
High Grade
2/2, 3/3
Poorly Differentiated
(BR high grade)
3