histologic grade
Pathological assessment of tumor cell differentiation and growth pattern indicating biological aggressiveness.
Full Definition
Histologic grade is a pathological evaluation system that assesses how closely cancer cells resemble normal cells and how rapidly they are dividing. Grading systems vary by cancer type but generally range from low-grade (well-differentiated, slower-growing) to high-grade (poorly-differentiated, rapidly-growing). Common grading systems include the Nottingham system for breast cancer, Gleason score for prostate cancer, and three-tier systems (Grade 1-3) for many carcinomas. Histologic grade provides prognostic information and influences treatment decisions, with higher grades typically indicating more aggressive tumors requiring more intensive therapy.
Usage
Usage note: Distinguish from clinical staging - grade refers to cellular characteristics, stage to tumor extent.
In Context
- "Pathology revealed invasive ductal carcinoma, histologic grade 2 of 3." — Pathology report
- "The high histologic grade influenced the decision for adjuvant chemotherapy." — Treatment planning notes