Page 736 - Textbook of Pathology, 6th Edition

720 5. Invasion. One of the important diagnostic features of (WHO) histologic grading categorising prostate cancer into
malignancy in prostate is the early and frequent grade I (well-differentiated), grade II (moderately
occurrence of invasion of intra-prostatic perineural spaces. differentiated) and grade III (poorly differentiated) has
Lymphatic and vascular invasion may be present but are largely been replaced with Gleason’s microscopic grading
difficult to detect. system which is based on two features:
i) Degree of glandular differentiation.
SPREAD. The tumour spreads within the gland by direct ii) Growth pattern of the tumour in relation to the stroma.
extension, and to distant sites by metastases. These features are assessed by low-power examination
of the prostatic tissue. For clinical staging of prostate cancer,
Direct spread. Direct extension of the tumour occurs into TNM system is considered international standard.
the prostatic capsule and beyond. In late stage, the tumour
may extend into the bladder neck, seminal vesicles, trigone The diagnosis of prostatic carcinoma is made by
and ureteral openings. cytologic, biochemical, radiologic, ultrasonographic and
pathologic methods. However, definite diagnosis is
Metastases. Distant spread occurs by both lymphatic and established by histopathologic examination of transrectal
haematogenous routes. The rich lymphatic network ultrasound (TRUS)- guided core needle biopsy.
surrounding the prostate is the main mode of spread to the Two serum tumour markers employed commonly for
sacral, iliac and para-aortic lymph nodes. The earliest diagnosis and monitoring the prognosis of prostatic
metastasis occur to the obturator lymph node. Haemato- carcinoma are as under:
genous spread leads most often to characteristic osteoblastic
osseous metastases, especially to pelvis, and lumbar spine; Prostatic acid phosphatase (PAP) is secreted by prostatic
other sites of metastases are lungs, kidneys, breast and brain. epithelium. Elevation of serum level of PAP is found in cases
The route of blood-borne metastases may be retrograde of prostatic cancer which have extended beyond the capsule
spread by prostatic venous plexus or via systemic circulation. or have metastasised. PAP can also be demonstrated in the
normal prostatic tissues.
CLINICAL FEATURES. By the time symptoms appear, the Prostate-specific antigen (PSA) can be detected by
carcinoma of prostate is usually palpable on rectal immunohistochemical method in the malignant prostatic
examination as a hard and nodular gland fixed to the epithelium as well as estimated in the serum. A reading
surrounding tissues. In such symptomatic cases, clinical between 4 and 10 (normal 0-4 ng/ml) is highly suspicious
features are: urinary obstruction with dysuria, frequency, (10% risk) but value above 10 is diagnostic of prostatic carci-
SECTION III
retention of urine, haematuria, and in 10% of cases pain in noma. PSA assay is useful in deciding whether the metastasis
the back due to skeletal metastases. originated from the prostate or not. PSA assay is also helpful
Clinical staging of carcinoma prostate takes into account in distinguishing high-grade prostatic cancer from urothelial
the following: carcinoma, colonic carcinoma, lymphoma and prostatitis.
The tumour found incidentally or a clinically unsuspected PSA level is generally higher in low-grade tumours than in
cancer in prostate removed for benign disorder (Stage A). high-grade tumours.
Treatment of prostatic carcinoma consists of surgery,
The tumour palpable by rectal digital examination but radiotherapy and hormonal therapy. The hormonal depen-
confined to the prostate (Stage B). dence of prostate cancer consists of depriving the tumour
The tumour has extended locally beyond the prostate into cells of growth-promoting influence of testosterone. This can
the surrounding tissues (Stage C). be achieved by bilateral orchiectomy followed by
Systemic Pathology
The tumour is associated with distant metastases administration of oestrogen. Surgical approaches for prostate
(Stage D). cancer include transurethral resection (TUR), radical
Clinical staging has good correlation with histologic prostatectomy and transurethral US-guided laser-induced
grading and, thus, has a prognostic significance. Mostofi’s prostatectomy (TULIP).

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