Grading in superficial papillary bladder carcinoma, with an emphasis on nuclear orientation.

OBJECTIVE: To develop a computerized analysis method that could reflect not only cellular anaplasia but also the orientation (PV) of neoplastic elements and could allow the separation of low (grade G 1 and G 2a) and high (G 2b) grades of superficial papillary bladder tumors (SPBTs). STUDY DESIGN: Cellular anaplasia is based on classic morphometric parameters, such as mean and standard deviation of area, perimeter, roundness and aspect ratio (length/width ratio) of 50 papillary bladder tumors (16 G 1, 10 G 2a and 24 G 2b according to Pauwels). Orientation of the major axis of each nucleus with respect to the true basal membrane was calculated using the SD of valve distribution. RESULTS: No statistically significant differences were found between cases showing contiguous grades (G 1 versus G 2a or G 2a versus G 2b). PV, SD of the area and SD of the perimeter were the parameters that could significantly distinguish between G 1 and G 2b and between G 1 plus G 2a and G 2b (P < .05). When comparing G 1 with G 2a plus G 2b, only PV and SD of the area were statistically significant. CONCLUSION: Quantification of the irregularities in the orientation of nuclei with respect to the basal membrane may improve morphometric classification of low grade SPBTs.