Prostate

Question 1

What are some features of Nodular Hyperplasia of the prostate?

Answer 1

Expression of p27 (negative in normal prostate)

Transition zone

Hyperplasia of stromal and glandular tissue; may contain corpora amylacea;
stromal component contains more smooth muscle and less elastic tissue than neoplastic

Question 2

Name benign mimics of prostatic carcinoma

10 listed

Answer 2

Florid hyperplasia of mesonephric remnants

Xanthoma / foamy macrophages

Extramedullary hematopoesis (in myelofibrosis)

Atrophy

Partial Atrophy (the most common mimic - basal cell markers may be lost and cytoplasm may stain for AMACR)

Basal cell hyperplasia

Clear cell cribriform hyperplasia good to know

Sclerosing Adenosis

Adenosis

Radiation changes

Question 3

How does the prostate normally stain for CK7 and CK20?

Answer 3

CK7 / CK 20 negative

Question 4

What organs are negative for CK 7 and CK 20?

Answer 4

Liver
Kidney
Prostate
Adrenal

Question 5

What are (4) prostatic basal cell markers?

Answer 5

34BE12 / CK903

GATA3

CK5/6

P63

Question 6

What is the threshold above which PSA should be monitored, with performance of biopsy if it continues to rise?

Answer 6

4.0 mg/mL

Question 7

In what region of the prostate does carcinoma typically arise?

Answer 7

Peripheral Zone

Question 8

What are the (3) pathognomonic histological signs of prostate cancer?

Answer 8

Circumferential perineural invasion

Glomeruloid formation

Mucinous fibroplasia / collagenous micronodules

not pathognomonic but good hint: crystalloids, wispy blue mucin.

Question 9

What are the (3) histologic types of prostatic carcinoma listed in the CAP protocol?

Answer 9

Acinar adenocarcinoma
Ductal adenocarcinoma
Small-cell neuroendocrine carcinoma

Question 10

Name some other histologic types of prostatic carcinoma

Answer 10

Pure squamous cell carcinoma

Adenosquamous

Mucinous

Small cell neuroendocrine carcinoma

Signet ring carcinoma

Basal cell carcinoma / adenoid cystic carcinoma

Adenoid basal cell tumor

lymphoepithelioma-like

Sarcomatoid

Question 11

Name some histologic variants of acinar adenocarcinoma

Answer 11

Foamy gland carcinoma

Prostatic adenocarcinoma with atrophic features

Pseudohyperplastic prostatic adenocarcinoma

PIN-like adenocarcinoma

Aberrant p63-expressing adenocarcinoma

Question 12

What is ASAP?

Answer 12

Atypical Small Acinar Proliferation

Frequent problem in prostatic biopsies. Foci of small atypical glands that are suspicious but not diagnostic of carcinoma.

4 - 6% of biopsies

Warrants second biopsy

Question 13

What are the histologic features of ductal prostatic adenocarcinoma?

Answer 13

Architecture: papillary and cribriform

Lined by columnar pseudostratified malignant epithelium

Intact basal cells

More advanced stage at presentation

May present as macrocystic, or as small prostatic urethral polyps

Question 14

What is the immunoprofile of prostatic adenocarcinoma?

Answer 14

PSAP + (more sensitive, less specific, also stains rectal carcinoid!)
PSA + (more specific)
NKX3.1 +
AMACR (racemase): PIN and invasive carcinoma +; not used for evaluation of metastasis

Basal cell markers: absent in prostate cancer, present in adenosis, PIN: p63, p40, HMWCK (CK 5/6, 34BE12)

Question 15

Name some benign entities that can stain with AMACR

Answer 15

adenosis (10%)
nephrogenic adenoma (60%)
partial atrophy (25%)

Question 16

Is AMACR always positive in prostate carcinoma?

Answer 16

No.
Negative in: 
20% of conventional
65% of foamy gland
65% of atrophic
75% of pseudohyperplastic

Always use in combination with basal cell markers for prostate Ca and do not use for the origin of metastasis.

Question 17

What are some histologic features of PIN?

Answer 17

Only high-grade is reported.

More basophilic than surrounding glands
high N:C
nuclear crowding
amphophilic cytoplasm
large nuclei with NUCLEOLI (should see at 20x)

Arhictectural variations: tufting, micropapillary, cribriform, flat/atrophic

Cytologic variations: foamy, hobnail

HGPIN found in step sectioned prostatectomies 59 - 100% of the time; may have high predictive value for presence of carcinoma. Does not often change follow-up protocols.

LGPIN common, not reported.

Question 18

What are the features of INTRAductal carcinoma?

Answer 18

High-grade cancer colonizing glands, beyond HGPIN architecturally and cytologically.

ROSAI: Malignant epithelial (prostatic secretory) cells filling large prostatic acini or ducts, with at least partial preservation of basal cells, forming either:

1) solid or dense cribriform patterns
2) loose cribriform patterns or micropapillary with marked nuclear atypia (6x normal size) or nonfocal comedonecrosis.

PTEN protein loss by immunohistochemistry (not widely used)

IDC NOT factored into Gleason grading, but IS reported.

Question 19

Features to distinguish intraductal (IDC) from ductal adenocarcinoma of the prostate?

Answer 19

Ductal: true papillary architecture
neoplastic cells with pseudostratified columnar morphology

vs.

IDC: cuboidal cells, round nuclei.

Question 20

Features to distinguish invasive acinar adenocarcinoma with cribriform architecture from IDC?

Answer 20

Acinar adenocarcinoma: more irregular distribution, other patterns of invasion, more variation in size and shape of cribriform structures, absence of basal cells.

NB: to tell from HGPIN: IDC should bridge the entire intraluminal space; extension into adjacent ducts also a hint.

Question 21

Define pT1, pT2, pT3 and pT4 in prostate resection specimens.

Answer 21

pT1: Does not exist ! no pT1 in prostate.
pT2: organ-confined
pT3a: extraprostatic extension or microscopic invasion of bladder neck
pT3b: invades seminal vesicles
pT4: Tumor is fixed or invades adjacent structures other than seminal vesicles (ex. external sphincter, rectum, bladder, levator muscles, and/or pelvic wall)

Question 22

how are lymph nodes staged in prostate cancer (N stage)?

Answer 22

pN1: metastasis to regional nodes.

pM1a = mets to non-regional nodes.

Question 23

What morphology (4) defines Gleason 4?

Answer 23

Poorly formed
Fused
Cribriform
Glomerulations

Question 24

What morphology defines Gleason 5?

Answer 24

Lack gland formation
sheets
cribriform glands with central comedonecrosis
single infiltrating cells (mimics lobular breast)