Prostate pathology

Question 1

Macroscopic appearance of prostate cancer

Answer 1

• 70% arise in PZ
• Cream-grey mass
• Gritty and firm
• Extra prostatic extension may be seen

Question 2

What is the Gleason grade based on?

Answer 2

Histological pattern on H+E stain

Grades based on major and minor criteria

Major:
1. morphological glandular architecture
2. absence of basal cells
3. nuclear atypia and pleomorphism

Question 3

How is the Gleason score derived?

Answer 3

Biopsy sample:
Sum of the most prevalent pattern (primary) and any amount of the worst pattern seen (Secondary)

RP specimen:
Sum of primary (most common) and secondary (second most common)

• any higher grade minor pattern (i.e. 3rd most common) >5% should be made the 2nd score in reporting

Question 4

When is a tertiary pattern reported for Gleason score

Answer 4

Only with an RP specimen

If a minor pattern constitutes <5%, it should be mentioned as a tertiary pattern

Question 5

What is the IHC profile of prostate cancer?

Answer 5

HMWCK -
p63 -
Cytokeratin 5/6 -
(^ above staining for basal cells)

AMACR +
PSMA +

Question 6

What are the histological subtypes of prostate cancer?

Answer 6

• Acinar Adenocarcinoma (>90-95%)
• Ductal adenocarcinoma (~5%)
• Prostatic urothelial carcinoma
• small cell Neuro-endocrine carcinoma
• large cell near endocrine carcinoma
• Adeno-squamous carcinoma
• SCC
• Basal cell carcinoma

Question 7

Micro Features of Grade 3 acinar adenocarcinoma

Answer 7

• Variable sized discrete/ separate glands
• Frequently small glands but with regular contours and uniform round lumens
• Focus is not circumscribed, cancer glands infiltrate in between benign gland

Question 8

Micro features of Grade 4 acinar adenocarcinoma

Answer 8

• Fused glands
• Cribriform glands with regular or smooth contours are now classified pattern 4
• Ill-defined, poorly formed glands with slit-like lumen
• Glands with intraluminal glomerulation

Question 9

Micro features of grade 5 acinar adenocarcinoma

Answer 9

• Solid nest of tumours with no/ occasional glandular space
• Tumour cells infiltrating in small nests, cords, or individual cell
• Solid nests with comedonecrosis

Question 10

What is intra-ductal prostate carcinoma associated with?

Answer 10

• high grade and high volume carcinoma (median GS 8 and T3 stage)
• increased risk of EPE, SVI and Pelvic lymph node mets
• independent indicator of early biochemical relapse and metastatic failure rate after RT

Question 11

What are the major microscopic criteria for diagnosis of prostatic adenocarcinoma?

Answer 11

Architectural: infiltrative small glands OR cribriform glands too large or irregular to be high grade PIN

Single cell layer (absence of basal cells)

Nuclear atypic: nuclear and nucleolar enlargement

Question 12

What words are used to describe the micro appearance of glands in grade 4 Gleason adenoCa

Answer 12

cribriform
poorly formed,
fused
glomeruloid

Question 13

Describe the micro appearance of grade 5 adenocarcinoma

Answer 13

sheets of tumour,
individual cells, cords, linear arrays and solid nests

Question 14

What IHC panel can be used to differentiate prostate adenoCA vs urothelial carcinoma?

Answer 14

All positive in prostate:
PSA
PAP (prostatic acid phosphatase)
Prostein
NKX3.1

All positive in urothelial:
GATA3
p63
HMWCK

Question 15

What IHC can be used to differentiate prostate adenoca vs bladder adenoca?

Answer 15

Positive for prostate:
- PSA
-PAP
-Prostein

Positive for bladder:
- Villin
- thrombomodulin
- CDX2
- CEA

Question 16

What variants of acinar adenocarcinoma have a worse prognosis than usual acinar AdenoCA?

Answer 16

signet ring like cell

Pleomorphic giant cell

Sarcomatoid

Question 17

Benefit of ISUP grade over Gleason score

Answer 17

• grading is simplified into 5 groups rather than 12
• the grade groups provide better stratification of risk compared with standard Gleason score of 6 vs 7 vs 8-10
• Gleason score 6 which suggests an intermediate score, is more appropriately described as Gr1, clarify the indolent nature of this to other doctors and patients

Question 18

Advantages/disadvantages of Gleason score

Answer 18

Advantages:
- prognostic
- widely used in nomograms
- established and internationally used

Disadvantages:
- inter observer variability
- definitions changed over times
- 12 categories which make risk stratification difficult/communication with patient difficult
- based on morphology only
- can be affected by sampling error

Question 19

Are ISUP groups validated prognostic groups

Answer 19

Yes