Molavi Chapter 11 - Prostate Flashcards
Approach to prostate core biopsy
Scan on low power and look for glands that stand out.
Atypical glands may be crowded, cribriformed, blue, or have blue mucin or dense pink secretions. Prostate cancer typically does NOT have a strong desmoplastic response.
Low power features of benign glands include irregularly shaped glands with “frilly” papillary infoldings, glands with a modest amount of intervening stroma, and presence of corpora amylacea (suggesting well-functioning glands).
Corpora amylacea
Concentrically laminated secretions associated with benign glands
Prostate carcinoma
Note the thick, pink secretions, distinct “cherry red” nucleoli, straight, crisp luminal borders, and enlarged and/or hyperchromatic nuclei.
Architecturally, prostate carcinomas lack a basal cell layer, which can be confirmed by immunostain (similar to loss of myoepithelial layer in breast cancer).
Sure features of cancer include perineural invasion (malignancy within the nerve sheath), mucinous fibroplasia, and glomeruloid forms.
Perineural invasion
In order to count as perineural invasion, the nerve must be within the nerve sheath.
Often the gland will fill up the nerve sheath circumferentially so it appears that the nerve is flowing directly through a gland! (as seen here)
A sure sign of prostate malignancy.
Mucinous fibroplasia
Hyalinized whorls of organized mucin within the gland lumen
Sometimes the surrounding gland epithelium may be compressed and indistinct. This is analogous to collagenous spherulosis in the breast.
A sure sign of prostate malignancy.
Glomeruloid forms in the prostate
Proliferative tangles of cells projecting into the larger gland lumen, resembling a glomerulus
A sure sign of prostate malignancy.
Gleason Grading
Base score: Assigned a number 3-5. Represents the most prevalent architecture.
Second score: Assigned a number 3-5. Represents the highest scoring additional architecture if on BIOPSY. If on radical prostatectomy, it represents the second most prevalent architecture.
Third score: Assigned only for radical prostatectomy specimens. Represents any additional third component of higher grade (almost always in the case of 3+4+5 or 4+3+5).
Thus, gleason scores range from 6 (3+3) to 10 (5+5).
- 3 represents well-differentiated with well-formed glands (you can draw a circle around each gland).
- 4 represents moderately differentiated (it is attempting gland formation) with cribriforming or poorly formed lumens.
- 5 represents poorly differentiated with total absence of gland differentiation, like sheets, single cells, or cords of cells.
There used to be a score from 1-5, with 5 being least differentiated. 1 and 2 have fallen out of use, leaving a base score of 3-5.
This biopsy is taken from the prostate. Assuming the pattern is consistent, what is the Gleason score?
Gleason 4 is the dominant pattern, and there may be a bit of Gleason 3. Note the cribriforming and poor gland formation.
Different people would call this either 4+3 or 4+4
Either way, this is prostate carcinoma for sure
This biopsy is taken from the prostate. Assuming the pattern is consistent, what is the Gleason score?
Individual cells are seen and there is no trace of any architecture resembling a gland.
Thus, this is a strong Gleason 5 + 5
This biopsy is taken from the prostate. Assuming the pattern is consistent, what is the Gleason score?
This is a fairly well-differentiated prostate cancer, coming in at a strong Gleason 3+3 with its nice gland formation.
Note the thick pink intraluminal material and blue mucin, secretory hallmarks of a prostate cancer.
Gleason grade groups
Once x+x scores have been assigned, these groups divide them into their prognoses
Group 1 (6) has an excellent prognosis, while group 5 (9-10) has a poor prognosis.
Features of prognostic importance in prostate cancer
- Gleason score
- Number of involved cores / Total examined cores
- Percent involvement on each core (not among cores)
- Linear extent of tumor out of total core length
- Perineural invasion
- Extraprostatic extension (malignant glands seen in extraprostatic fat)
How to think about pancreatic intraepithelial neoplasia
It is thought to be a precursor to cancer and demonstrate increased risk of malignancy, but has not been shown to warrant immediate rebiopsy or excision.
For this reason, PIN in the setting of prostate carcinoma is irrelevant, but PIN in the absence of carcinoma may lead to closer follow-up.
Only high-grade PIN is worth mentioning.
High grade prostatic intraepithelial neoplasia (PIN)
Glands are large with prominent papillary or micropapillary luminal surfaces, similar to benign architecture. Nuclei are enlarged, elongated, and hyperchromatic. By definition nucleoli are visible at 20x. Basal cell layer is still present, but often patchy.
Cribriform PIN may be seen, but back to back glands are not PIN – that’s cancer.
Prostate adenosis
Literally “proliferation of glands.” A hyperplastic lesion, not a neoplastic one.
Consists of a lobular group of crowded glands. Individual cells should be similar between hyperplastic glands and normal glands. May have visible small nucleoli but by definition they have a clear basal layer (may require immnostains to see it though).
Prostate atrophy
Shrinkage of the cytoplasm in prostate glands. Appears to leave rows of lined nuclei at low power, which may look irregular and suspicious. Lumens take on a “staghorn” appearance. Corpora amylacea are present.
Lack of cytoplasm should be a red flag against diagnosing this as cancer. Immunostains will highlight a nice basal cell layer.
Basal cell hyperplasia
Proliferation and activation of the basal cells which underlie glandular cells.
When noticeable, they have a denim-blue/gray, oval, regular nucleus surrounding more purple glandular nuclei.
Immunostains also help.
Cowper’s glands
Normal glands distal to the prostate that secrete directly into the urethra. They are not normally sampled on needle biopsy, but sometimes accidentally find their way in.
They are lobular in architecture with small, bland nuclei. Their abundant mucin will stain with periodic acid-Schiff and negative for prostate markers (PSA and prostate-specific acid phosphatase).
Sclerosing adenosis
Best seen in transurethral resection specimens.
Hyperplastic and proliferative lesion that is complicated by a hypercellular stroma. Cells appear as crowded glands and have prominent nucleoli.
Remember that true prostate cancer does NOT induce a desmoplastic reaction.
Racemase
Preferentially stains the cytoplasm of prostate cancer cells
Prostatic ductal adenocarcinoma
A variant type of prostatic adenocarcinoma characterized by tall, stratified columnar cells making papillary or cribriform structures.
May grow into the urethra as exophytic masses or may arise from peripheral ducts in the prostate. Sometimes is found in conjunction with conventional prostate adenocarcinoma.
Typically considered as a Gleason 4 pattern. If comedo necrosis is present, it bumps it to Gleason 5.
Normal prostate histology
Intraductal carcinoma of the prostate
Large glands with lumen-spanning atypical cells, but also with a preserved myoepithelial cell basal layer (sometimes patchy, but present).
4 specific features:
* solid architecture
* dense cribriform architecture
* 6 or more markedly atypical nuclei adjacent to benign nuclei
* non-focal comedonecrosis
Glomerular prostate growth
Specific to prostate adenocarcinoma
Mucinous fibroplasia
Specific to prostate adenocarcinoma
Perineural invasion
Specific to prostate adenocarcinoma
Gleason scores
Prostatic basal cell carcinoma
Normal luminal cells, malignant surrounding cells that may separate and grow into nests.
Architecture: Adenoid cystic, cribriform, and basaloid pattern. Unlike adenocarcinoma, prostatic BCC often involves a desmoplastic stromal response.
IHC: p63+, PSA negative
Labs: Non-elevated PSA
Prostate lipofuscin pigmentation
Fairly common finding in the prostate which does not provide any diagnostic information – just know that it can happen.
Ganglion cells sampled from within the prostate
Usually at one of the ends of the core biopsy. They have a typical ganglion cell appearance.
Paraganglion cells sampled from within the prostate
These guys can be very tricky. Just remember that they are out there. They will be PSA/PSAP negative and strongly S100+.
