Cytologic nuclear grade of malignant breast aspirates as a predictor of histologic grade. Light microscopy and image analysis characteristics.

OBJECTIVE

To determine if cytologic nuclear grade characteristics combined with image analysis assessment of morphometric nuclear parameters (1) correlate with the modified Scarff-Bloom-Richardson grading system and (2) discriminate between low and high nuclear grades of invasive ductal carcinoma.

STUDY DESIGN

Fifty-four fine needle aspiration biopsies (FNABs) of breast carcinoma were evaluated for five morphologic nuclear grade characteristics. In addition, four morphometric, standardized object measurements were analyzed by an image analysis system. Corresponding biopsies of invasive ductal carcinoma (46 cases) were independently evaluated with the Scarff-Bloom-Richardson grading system, modified into low (scores 3-6) and high (scores 7-9) grades.

RESULTS

An overall agreement of 82% was reached by three of four cytopathologists for each of five morphologic characteristics. There was a strong correlation (r = .8059, P < .0001) between cytologic nuclear grade and modified histologic grade. Only pleomorphism, nucleoli and sum optical density retained their statistical significance in distinguishing low from high grade ductal carcinomas. These three characteristics also had the strongest correlation with cytologic nuclear grade.

CONCLUSION

Cytologic nuclear grade from aspirates of ductal carcinoma can be a predictor of the modified histologic grades of Scarff, Bloom and Richardson. Nuclear morphology reinforced by image morphometry may separate these tumors into low and high nuclear grade categories.