Prostate Flashcards
Prostate cancer
The most COMMON SOLID TUMOR IN MEN
1/6 over the age of 50 will be diagnosed in their lifetime
1/33 will die from it
Normal Prostate Anatomy
Borders the bladder (anterior) and the rectum (posterior)
Digital rectal exam is good for tumors of the prostate because MOST ARISE IN THE POSTERIOR PORTION and feel like HARD NODULES –> most common condition, BPH, is palpated as SOFT NODULES
Tumors tend to arise in the TRANSITIONAL ZONE or in the PERIURETHRAL GLANDS –> reason why BPH tends to cause outflow obstruction
Histology –> Many STELLATE GLANDS in a FIBROMUSCULAR STROMA
Lined by a SINGLE LAYER OF COLUMNAR EPITHELIUM with abundant PINK CYTOPLASM
FLATTENED BASAL LAYER –> very important in cancers because it is LOST IN CANCEROUS GLANDS, but MAINTAINED IN BPH/benign conditions
Visualize Basal Layer with CYTOKERATIN STAIN
Acute Bacterial Prostatitis
Relatively uncommon and occurs most often as a result of a GRAM NEGATIVE INFECTION that spreads from the BLADDER
Associated with SYSTEMIC SIGNS and glands are infiltrated by NEUTROPHILS
Chronic Prostatitis
Symptoms of urgency and frequency without systemic signs –> think chronic
Massage prostate to collect secretions for phase microscopy –> >10 neutrophils per visual field = prostatitis
Culture the specimen –> growth of bacteria indicates CHRONIC BACTERIAL PROSTATITIS (also caused by gram negatives/UTI, but presents with local symptoms, such as suprapubic pain)
NO GROWTH = chronic ABACTERIAL prostatitis; most common form; caused by FASTIDIOUS BACTERIA –> Chlamydia, Mycoplasma, Ureplasma –> INTRACEULLAR and don’t grow on culture; send for ELISA
Abacterial is common in YOUNG, SEXUALLY ACTIVE males and presents with SILENT or MILD local symptoms
Usually discovered after PSA –> inflammatory cells that infiltrate the glands can cause increased release of PSA –> LYMPHOCYTE INFILTRATION
Granulomatous Prostatitis
Rare, caused by TB, BCG, Fungi, or post-trans urethral resection of the prostate
TB/Fungal –> only in immunocompromised
BCG Vaccine (for TB) –> common in men who are being treated for transitional cell carcinoma of the bladder
Post-TURP (transurethral resection) –> patients develop a secondary prostatitis –> tissue death after procedure causes HISTIOCYTES to pallisade around the area of necrosis –> pallisading granulomatous rxn
BPH Overview
VERY common condition –> almost all males over 30 have some proliferation, and half of men over 50 have some level of BPH
Both the GLANDS (mostly) and the FIBROMUSCULAR STROMA (sometimes) can proliferate
Most cases are silent, but symptoms if present can RECUR and cause URINARY RETENTION (obstructs)
BPH also predisposes to UTI and can cause OBSTRUCTIVE UROPATHY by leading to a thickening of the muscular layer of the bladder
Pathogenesis of BPH
Development has been shown to be dependent on SYNERGISM between ANDROGENS and ESTROGEN –> castration of dogs showed lower incidence!!!
Testosterone on its own has NO ROLE, until it is converted to DHT by 5-alpha reductase –> then it acts on intra-nuclear androgen receptors in both STROMAL and EPITHELIAL CELLS to cause production of a growth factor that induces these cells to proliferate
Histology shows INCREASED # of GLANDS, much closer together
Treatment of BPH
Treatment by trans-urethral resection of the prostate results in LITTLE FREGMENTS of prostatic tissue to be submitted for analysis
If cancer is found, it can then be staged by counting how many of these fragments have cancer tissue
PROSTATECTOMY may be done –> associated with more morbidity –> loss of ability to ejaculate and impotence, due to an innervation disturbance
Specimens can show the NODULAR APPEARANCE of the prostate
Some of these nodules can outgrow their blood supply and undergo COAGULATIVE NECROSIS –> causes a SPIKE IN PSA
PROSTATIC CARCINOMA
Most common cause of cancer in men –> SECOND LEADING CAUSE OF CANCER DEATH (lung #1, obv)
Most common in blacks, least common in asians
Hard nodule is felt on DRE if localized posteriorly
Carcinoma is usually ASYMPTOMATIC except for URINARY OBSTRUCTION/METASTASIS (which is usually to bone)
PSA
Prostate-specific antigen –> an ENZYME released from the prostate with semen that causes LIQUEFACTION of the ejaculat and has MUCOLYTIC ACTION in the cervix to facilitate fertilization
Patients should be RESTRICTED from ejaculation for a week before because it causes a release of PSA, and may cause false positive!
If cancer found, patient must undergo a metastatic workup, because metastatic disease is incurable and there would be no need for a prostatectomy
Why is there such a fuss with PSA?
May be INACCURATE and can lead to OVER-TREATMENT; but some aggressive cancers are indeed caught by the test
PSA level > 4 is somewhat worrisome
PSA level > 10 is VERY worrisome
Total-to-free PSA ratio is more specific than the standard total PSA –> HIGH PERCENTAGE of FREE PSA = DECREASED PROBABILITY OF CANCER!!!! (0-10% free = 56% chance cancer; >25% free = 8% cancer)
High RATE OF INCREASE in PSA is concerning too
Prostatic Intraepithelial Neoplasia
PIN is a MALIGNANT transformation of glands that leads to INTRADUCTAL PROLIFERATION OF ATYPICAL CELLS and is still limited by a BASAL LAYER
Cells have not yet invaded the stroma, but the high grade lesions are considered PRECURSORS to prostatic adenocarcinoma
Classification of PIN
Low or High grade and is equivalent to DCIS of the breast
Diagnosis of PIN demands CLOSE FOLLOW UP as 1/3 of the lesions will progress to cancer within 10 years!!!
Incidence of PIN is 9% and INCREASES with age
Remember – cancerous glands will LOSE THE BASAL LAYER
Types of Prostate Cancer
ADENOCARCINOMA (glandular, epithelial), Not Otherwise Specified (NOS) and Adenocarcinoma Ductal Type
95% of prostate cancers
GROSS –> tan-yellow, firm nodules; usually in the periphery of the gland
HISTO –> malignant glands are SMALL, NUMEROUS and in contact with each other
Usually lined by a SINGLE LAYER OF ATYPICAL CELLS with PROMINENT nucleoli, and LACK A BASAL LAYER (don’t stain with keratin)
Also tends to invade around the nerves –> perineural invasion –> likelihood of paraprostatic invasion (spread beyond the prostate) is HIGH in these cases
Other types of cancer in the prostate
Transitional cell (same as in bladder), Squamous cell carcinoma, small cell carcinoma (very aggressive), adenoid/basal type carcinoma, carcinosarcoma and other types
