Stereologic estimates of nuclear volume in noninvasive bladder tumors (Ta) correlated with the recurrence pattern.

The mean nuclear volume of cells in bladder tumors was estimated using the principle for estimation of the volume of particles of arbitrary shape. The study included three groups of patients: one group of 10 patients with only one nonrecurrent, noninvasive bladder tumor (Ta), another group of 11 patients with recurrent noninvasive bladder tumors, and a third group of 14 patients with recurrent primary noninvasive bladder tumors who ultimately developed an invasive tumor. After standard fixation, embedding, sectioning, and hematoxylin-eosin staining an unbiased estimate of the mean volume of nuclei sampled with a chance proportional to their volume was calculated: nu v = pi/3.l3(0). Here lo is the length of the intercept through a test point hitting a nucleus measured in a random direction through the test point. In the primary tumor the mean, nuclear volume of the cells in tumors from patients with a single bladder tumor is small (141 micrograms 3 geometric mean) with only one of ten above 165 microns 3. The mean nuclear volume of the primary tumor cells in patients with recurrent noninvasive bladder tumors was slightly larger (195 microns 3 geometric mean) with five of 11 above 165 microns 3. The mean nuclear volume of the primary tumor cells in patients who ended up with invasive tumors was higher (245 microns 3 geometric mean) with 12 of 14 above 165 microns 3. A large mean nuclear volume of cells in noninvasive bladder tumors (Ta) indicates recurrence and an invasive potential. Considering that nearly all primary tumors were classified as Bergkvist Grade II tumors, the prognostic precision of absolute mean nuclear volume is noticeable. This simple and fast estimate of mean nuclear volume seems to provide objective data with high prognostic value in primary noninvasive bladder tumors (Ta).