Gleason's classification is used for

Refer Robbins page no Grading and Staging. Grading is of paicular impoance in prostatic cancer, because grade and stage (discussed below) are the best prognostic predictors. Prostate cancer is graded using the Gleason system, which stratifies pros- tate cancer into five grades on the basis of glandular pat- terns of differentiation. Grade 1 represents the most well differentiated tumors, in which the neoplastic glands are uniform and round in appearance and are packed into well-circumscribed nodules (Fig. 21-38A). In contrast, grade 5 tumors show no glandular differentiation, with tumor cells infiltrating the stroma in the form of cords, sheets, and nests (Fig. 21-38C). The other grades fall in between these extremes. Most tumors contain more than one pattern; in such instances, a primary grade is assigned to the dominant pattern and a secondary grade to the second most frequent pattern.