Pathology of the Prostate

PathoBasic 24.01.17

Tatjana Vlajnic

Overview

• Adenocarcinoma of the prostate

– Grading

– Special variants

• Mimickers of prostate adenocarcinoma

– Atrophy

• Inflammatory conditions

– Granulomatous prostatitis

Overview

• Adenocarcinoma of the prostate

– Grading

– Special variants

• Mimickers of prostate adenocarcinoma

– Atrophy

• Inflammatory conditions

– Granulomatous prostatitis

Gleason patterns/grading

Original Modified 2015

2015: Gleason pattern 4

• Cribriform glands

• Glomeruloid glands

2015: New grading system

«WHO/ISUP Grad»

Overview

• Adenocarcinoma of the prostate

– Grading

– Special variants

• Mimickers of prostate adenocarcinoma

– Atrophy

• Inflammatory conditions

– Granulomatous prostatitis

Adenocarcinoma of the prostate

• Acinar adenocarcinoma

• Ductal adenocarcinoma

• Intraductal carcinoma (IDC-P)

Ductal adenocarcinoma (DAc)

• Tall pseudostratified columnar cells

• Periurethral area (exophytic mass)

• Admixed with acinar adenoca >> pure

• Overall incidence 3.2%

– Pure ductal adenocarcinoma: 0.2 – 0.4%

• Gleason grade 4: cribriform/papillary

• Long papillary fronds

• Pseudostratified columnar cells

• Papillary (commonly seen on TUR-P)

• Cribriform (slit-like lumina)

• Solid

• Individual glands (mimicking colonic adenoca)

• On core needle biopsy (fragmentation!)

• PIN-like ductal adenocarcinoma

AMACR / p63

• PIN-like ductal adenocarcinoma

Intraductal carcinoma (IDC-P)

• Not a precursor lesion

• Associated with high-grade, high-stage prostate carcinoma

• Overall incidence 2.8%

– Isolated on core biopsies: 0.06 – 0.26%

• Gleason grade should not be assigned

• Comment: Association with aggressive PrCa

IDC-P: Morphologic features

• Solid, dense cribriform, loose cribriform, micropapillary, flat

• Marked nuclear atypia and pleomorphism

• Nucleomegaly (≥6 times normal)

• Comedonecrosis, mitoses

HMWCK: basal cells

Overview

• Adenocarcinoma of the prostate

– Grading

– Special variants

• Mimickers of prostate adenocarcinoma

– Atrophy

• Inflammatory conditions

– Granulomatous prostatitis

Atrophy

• Mimicker of carcinoma (clinically/histology)

• Prostatic induration, suspicious on US

• Wide age range

• Distinct histologic variants:

– Simple atrophy

– Postatrophic hyperplasia (PAH)

– Partial atrophy

• Cave: active inflammation, post radiation!

Simple atrophy

• Basophilic appearance

• Glands with normal caliber /dilated

Postatrophic hyperplasia (PAH)

• Basophilic appearance

• Crowded glands, lobular

• High proloferation rate, mitoses

Postatrophic hyperplasia (PAH)

• Infiltrative pattern

• DD: atrophic variant adenocarcinoma!

HMWCK

Partial atrophy

• Lacks basophilic appearance

• Crowded glands with pale cytoplasm

Partial atrophy

• Nuclei spaced apart, undulating luminal surfaces

• Nuclei reach the full height of the cytoplasm

HMWCK: patchy staining

Immunohistochemistry

• p63, CK5/6 (basal cells)

• Tumor cells:

– AMACR+

– PSA(P)+

– ERG+ (50%)

– GSTpi – (75-100%)

– CK7–

Immunohistochemistry

Overview

• Adenocarcinoma of the prostate

– Grading

– Special variants

• Mimickers of prostate adenocarcinoma

– Atrophy

• Inflammatory conditions

– Granulomatous prostatitis

Granulomatous prostatitis

• Mimicker of carcinoma (clinically/histology)

• Prostatic induration, PSA elevation, suspicious on US/MRI

• Non-specific

• Post resection (TURP >> biopsy)

• Infectious (mycobacterial)

– Post-BCG, (systemic tuberculosis)

• Systemic

Non-specific granulomatous prostatitis

• Mixed inflammation incl. eosinophils

• No cesaeting granulomas

Non-specific granulomatous prostatitis

• Predominance of lymphocytes (cave DD

lymphoma!)

Non-specific granulomatous prostatitis

• Predominance of macrophages (DD high-

grade prostate carcinoma)

CD68 PanCK

References

• Epstein JI, et al. The 2014 International Society of Urological Pathology (ISUP) Consensus Conference on Gleason Grading of Prostatic Carcinoma: Definition of Grading Patterns and Proposal for a New Grading System. Am J Surg Pathol, 2016

• Tavora F, Epstein JI. High-grade prostatic intraepithelial neoplasialike ductal adenocarcinoma of the prostate: a clinicopathologic study of 28 cases. Am J Surg Pathol, 2008

• Guo CC, Epstein JI. Intraductal carcinoma of the prostate on needle biopsy: Histologic features and clinical significance. Mod Pathol. 2006 Dec;19(12):1528-35.

• Magers M, Kunju LP, Wu A. Intraductal Carcinoma of the Prostate: Morphologic Features, Differential Diagnoses, Significance, and Reporting Practices. Arch Pathol Lab Med. 2015 Oct;139(10):1234-41

• Wang W, et al. Partial atrophy on prostate needle biopsy cores: a morphologic and immunohistochemical study. Am J Surg Pathol, 2008

• Srigley JR. Benign mimickers of prostatic adenocarcinoma. Mod Pathol, 2004 • Hameed O, et al. Pseudoneoplastic mimics of prostate and bladder carcinomas.

Arch Pathol Lab Med, 2010 • Biopsy Interpretation of the Prostate, Epstein JI, 5th Edition