A breast mass biopsy shows tubule formation >75%, mild nuclear pleomorphism, and 0-1 mitosis/10 HPF. The Nottingham histological grade is:
- A Grade II (moderately differentiated)
- B Grade I (well-differentiated) ✓
- C Grade III (poorly differentiated)
- D Grade IV (anaplastic)
Correct answer: B. Grade I (well-differentiated)
Explanation
The Nottingham Grading System (Elston-Ellis modification) scores: (1) tubule formation — >75% scores 1; 10-75% scores 2; <10% scores 3; (2) nuclear pleomorphism — mild scores 1; moderate 2; marked 3; (3) mitotic rate — low scores 1; medium 2; high 3. Total score 3-5 = Grade I; 6-7 = Grade II; 8-9 = Grade III. The described features (>75% tubules=1, mild pleomorphism=1, 0-1 mitoses=1) give a score of 3, classifying as Grade I. There is no 'Grade IV' in breast cancer grading.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.