Characterization of cytoplasmic secretory granules (PSG), in prostatic epithelium and their transformation-induced loss in dysplasia and adenocarcinoma
Rj. Cohen et al., Characterization of cytoplasmic secretory granules (PSG), in prostatic epithelium and their transformation-induced loss in dysplasia and adenocarcinoma, HUMAN PATH, 29(12), 1998, pp. 1488-1494
Citations number
17
Categorie Soggetti
Research/Laboratory Medicine & Medical Tecnology","Medical Research Diagnosis & Treatment
Cytoplasmic clarity is a histological feature of normal prostatic secretory
cells, but in this study, tissue fixation in strong (>2.5%) glutaraldehyde
dramatically altered cytological staining. Secretory cytoplasm appeared re
d and granular on routine stains because of myriad intensely staining eosin
ophilic granules (PSG). Immunostaining for prostate-specific antigen (PSA)
and prostatic acid phosphatase (PAP) showed their exclusive localization to
the PSG. Electron microscopy confirmed these findings and also showed that
after fixation in many agents, including formaldehyde, PSG appeared empty,
accounting for the artefactual "clear cell" appearance on light microscopy
. PSG were most densely concentrated apically in a bud-shaped luminal compa
rtment in which cytokeratin was selectively absent. Normal exocrine secreti
on was visualized as detachment of apocrine buds or their in situ disintegr
ation. Distinctively in dysplasia and almost all carcinomas, PSG were rare
to absent, and proteases were free in the cytoplasm, often concentrated ben
eath the apical membrane. The apocrine compartment was absent, with no obse
rved secretory mechanism. Tumor cells had dark amphiphilic cytoplasm after
all fixatives. This provided a reliable method of distinguishing malignant
from benign glands in tissues fixed in strong glutaraldehyde. Clear cell ca
rcinomas, whose cytoplasm mimicked routinely fixed normal secretory cells,
surprisingly had almost no PSG. Instead, their "granules" were lipid-filled
vacuoles reflecting a secretory pathway not seen in normal cells, dysplasi
a, or the common "dark cell" carcinomas. These observations may define two
distinctive biological pathways of prostate cancer evolution and may facili
tate diagnostic decisions on needle biopsy samples. HUM PATHOL 29:1488-1494
. Copyright (C) 1998 by W.B. Saunders Company.