Stereological estimates of nuclear volume in the course of primary tumors of the renal pelvis.

The aim of this retrospective study was to provide quantitative data which make grading of primary tumors of the renal pelvis objective and reproducible by stereological estimation of nuclear volume using the principle of estimation of the mean volume of particles of arbitrary shape. The study includes 35 kidney specimens with primary transitional cell tumor of the renal pelvis. After standard fixation, embedding, sectioning and hematoxylin-eosin staining, an unbiased estimate of the mean volume of nuclei sampled with a change proportional to volume: (formula; see text) was calculated. Here 1(0) is the length of the intercept through a test point hitting a nucleus measured in a random direction. The mean nuclear volumes of the tumors are spread over a wide range, from 159 microns 3 to 1.555 microns 3. Ten of 11 patients with nuclear volume above 800 microns 3 died of the disease while only 8 of 24 patients with a mean nuclear volume below 800 microns 3 died of the disease. This simple and fast estimate of mean nuclear volume seems to provide objective data with a high prognostic value.