prostate pathology

prostate

zones
- transition zone: surrounds prostatic urethra, adjacent glands may have urothelial metaplasia
- central zone: surrounds ejaculatory ducts, glands here are complex and may mimick cribriforming
- peripheral zone: posterior and lateral
regions
- anterior: fibromuscular stroma
- posterior: contains the zones, cancer occurs here, especially transition and peripheral zones
- apex
- base
  - bladder neck: smooth muscle
  - seminal vesicles: has small invaginations mimicking malignant glands, muscular stroma, has pigment
glands
- 2 layers
- secretory cells: PSA+
- basal cells: p63+
- glands are large, intraluminal complexity
fibromuscular stroma
other
- contains skeletal muscle
- ganglion cells in extraprostatic tissue mimicks carcinoma

PIN mimicks
- PIN
- basal cell hyperplasia
- complex glands (base, ejaculatory duct, seminal vesicle, BPH)
Gleason 3 mimicks
- Gleason 3
- (partial) atrophy
- ASAP
- ductal carcinoma
- seminal vesicle adenocarcinoma
Gleason 4 mimicks
- Gleason 4
- intraductal carcinoma
- complex glands
Gleason 5 mimicks
Common benign
- BPH
- prostatitis
- BCG effect
- complex glands
Metastasis, soft tissue, hematolymphoid

Gleason
- Gleason 3 = discrete glands
- Gleason 4 = fused, cribriform glands
- Gleason 5 = solid sheets, single cells, comedo necrosis, karyorrhexis
- Total score for bx: most prevalent grade + 2nd or 3rd most prevalent pattern (pick the higher grade out of the two)
- For resections: give all grades and percent of each
Grade group
- 1: Gleason score 3+3=6
- 2: Gleason score 3+4=7
- 3: Gleason score 4+3=7
- 4: Gleason score 8
- 5: Gleason 9, 10
Bx caveats
- lower grade < 5% are ignored (Eg. 4+3 with minute 3 becomes 4+4)
- For Gleason 4+3 or 3+4, give % that is Gleason 4
- Gleason 4 has worse prognosis if has cribriform, so comment
- For bx, grade separately for each bx location
Resection caveats
- For multifocal resections, note each foci, but overall staging purposes, pick the worst from each nodule
- For resections, if tertiary grade is < 5%, change wording to minor high grade pattern

T1: microscopic
- T1a: incidental tumor, <= 5% specimen
- T1b: incidental tumor, > 5% specimen
- T1c: tumor on needle biopsy
T2: prostate confined (including capsule)
- T2a: unilateral, <= half of the involved side
- T2b: unilateral, > half of the involved side
- T2c: bilateral
T3: extraprostatic extension
- T3a: extracapsular extension, including microscopic bladder neck involvement
- T3b: seminal vesicle invasion (into muscular wall, not just surrounding stroma)
T4: adjacent structure invasion
- bladder neck
- external sphincter
- rectum
- levator muscles
- pelvic wall
M1: metastasis
- M1a: nonregional lymph node(s)
- M1b: bone
- M1c: other sites