Nuclear volume estimates in prostatic intraepithelial neoplasia.
OBJECTIVE
Prostatic intraepithelial neoplasia (PIN), the most likely precursor of prostatic adenocarcinoma, is divided into two grades, low and high. Pathologists may encounter difficulties in applying these criteria in daily practice. In view of the clinical significance of high grade PIN as strong predictor of carcinoma, the separation of low and high grade PIN plays an important role in patient management. The aim of the present study was to evaluate three-dimensional nuclear size estimation in normal prostatic glands, low and high grade PIN, and prostatic adenocarcinoma as an element in their classification.


METHODS
We studied 31 formalin-fixed, paraffin-embedded, whole-mounted radical prostastectomy specimens that contained foci of normal prostatic glands, low and high grade PIN, and prostatic adenocarcinoma. Hematoxylin-eosin-stained sections were selected for the stereologic estimation of volume-weighted mean nuclear volume by the "point-sampled intercepts" method. On each focus, an average of six fields of vision were systematically chosen.


RESULTS
The quantitative results indicate a significant increase in nuclear volume from normal prostatic glands (mean, 209.0 micron 3; SD, 64.6 micron 3) to low grade PIN, high grade PIN and prostatic adenocarcinoma with increments of 49%, 88% and 109%, respectively (F = 29.1, P < .001). Two-group comparisons (Duncan procedure) showed differences between low and high grade PIN and prostatic adenocarcinoma (P < .01). The difference between high grade PIN and prostatic adenocarcinoma was not significant.


CONCLUSIONS
Three-dimensional estimates of nuclear size discriminate low and high grade PIN. Lack of stereologic differences between high grade PIN and prostatic adenocarcinoma further supports high grade PIN as a precursor of prostatic adenocarcinoma.
López-Beltrán
A
A
Department of Pathology, Córdoba University Medical School, Spain. em1lobea@lucano.uco.es
Artacho-Pérula
E
E
Roldán-Villalobos
R
R
Luque-Barona
R
R
D000368:Aged; D002467:Cell Nucleus / Q000473:pathology* / Q000648:ultrastructure*; D003953:Diagnosis-Related Groups; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008853:Microscopy; D008867:Microtomy; D008875:Middle Aged; D010316:Particle Size; D019048:Prostatic Intraepithelial Neoplasia / Q000150:complications / Q000473:pathology / Q000648:ultrastructure*; D011471:Prostatic Neoplasms / Q000150:complications / Q000473:pathology / Q000648:ultrastructure*