BCH (ordinary, florid, and with nucleoli): differential diagnoses. Morphological criteria and major immunohistochemical findings
| Architecture | Cytology | 34βE12, p63 | PSA | S-100 protein, SMA | |
|---|---|---|---|---|---|
| BCH, basal cell hyperplasia; PIN, prostatic intraepithelial neoplasia; PSA, prostate specific antigen; SMA, α smooth muscle actin. | |||||
| BCH (ordinary, florid, and with nucleoli) | Cell nests, two cell layers minimum, solid or cystic | Small to medium sized nuclei, nucleoli may be prominent in some forms | + | ± | − to ± |
| High grade PIN | Ducts and acini with various archi-tectural patterns, ranging from flat to cribriform | Cells with enlarged nuclei, with a prominent nucleolus, similar to those in adenocarcinoma | ± (basal cells) | + | − |
| Adenocarcinoma | Acini of various sizes, either separated or fused, with different architectural patterns, such as flat or monolayered or cribriform | Cells with enlarged nuclei, with prominent nucleoli | − | + | − |
| Sclerosing adenosis | Acinar structures, predominantly small, lined by bilayered epithelium | Small to medium sized nuclei, inconspicuous nucleoli | + (basal cells) | + | + |
| Benign seminal vesicle/ejaculatory duct epithelium | Ducts lined by a bilayered epithelium | Prominent nuclear atypia and pleomorphism | + | − | − |
| Squamous metaplasia | Ducts and acini lined by multilayered epithelium similar to epidermis | Cells with small to medium sized nuclei, inconspicuous nucleoli; keratinisation often prominent | + | − | − |
| Transitional cell metaplasia | Ducts and acini lined by multilayered epithelium similar to urothelium | Small to medium sized nuclei, inconspicuous nucleoli; luminal cells larger than those in the intermediate and basal layers | + | − to ± (scattered luminal cells) | − |