Immunohistochemistry helps pathologists in the diagnosis of prostatic diseases, mainly carcinomas. Equally important, digital image analysis is being increasingly used to study alterations in the prostate. The present work aims to morphometrically quantify the immunostain of galectin-3 expressed in normal prostate (NP), benign hyperplasia (BH) and prostatic adenocarcinoma (PA) in humans. Immunohistochemistry was developed using monoclonal anti-galectin-3 antibody. Surgical specimens from different patients with BH (n = 12), PA (n = 10) and NP (n = 10) were fixed in formalin, processed and embedded in paraffin. Hematoxylin and eosin staining was used to confirm the diagnosis. Tissue slices (4µm) were incubated with anti-galectin-3 antibody solution for one hour at room temperature and then incubated with a secondary anti-body conjugated to peroxidase (30 minutes). The stain pattern was visualized with diaminobenzidine (DAB) and hydrogen peroxide. Image analysis was carried out using a workstation consisting of a standard light microscope equipped with a digitalizing camera connected to a desktop personal computer. Image storage and retrieval was managed using the OPTIMAS® software system. For prostatic adenocarcinoma cells a significant decreased (p < 0.001) staining pattern for galectin-3 was observed. Computer image analysis detected stained areas of atypic prostatic cells: BH (875.9 ± 52.1µm²), PA (120.2 ± 23.3µm²) and NP (238.4 ± 27.6µm²). The different patterns of galectin-3 expression distinguished the neoplasic cells from normal prostatic ones and significant alterations in the galectin-3 expression into the studied tumor lesions.
Prostate; Galectin-3; Digital image analysis; Tumour
