NLS-Diagnosis of Prostate Diseases
V.A. Toropova,
S.N. Petrenko
An ever growing number of physicians enjoy an opportunity of a screening NLS diacrisis of
prostate grand and urinary bladder. This article attempts to consider some particulars of
morphological changes occurring in a prostate affected by pathology, based on the results
of NLS-investigations.
In the West prostate cancer makes 20% of the total cancer diseases and ranks second to
lung tumors as a death cause.
According to some autopsy findings with a histological investigation of the prostate, 12-
47% of men aged over 50 appeared to have cancerous nidi. Clinically, cancer is
diagnosed more rarely because a high percentage of that number corresponds to ‘minor
forms’ of cancer that have low invasiveness, so the patients suffering from it die of
another kind of pathology.
To enhance the quality of prostate diseases diagnosis it is important to comprehend the
specifics of topographic and zonal anatomy of a particular organ.
The prostate gland is located in the small pelvis between the bladder and anterior
abdominal wall, anterior rectum wall and secondary urogenital diaphragm. The gland has
a chestnut shape and tightly envelops the bladder cervix and prostate urethra. The gland
base is lightly connected with the bladder into a coherent mass. Its anterior surface is
directed to the symphysis, and the posterior one - to the rectum ampulla. The posterior
surface of the gland has an expressed sulcus, which enables to conventionally subdivide
the gland into the left and right lobes. Besides, there is a protruding middle cone-shaped
lobe confirmed anteriorly by the prostatic urethra and by the spermatic ducts posteriorly.
According to zonal anatomy theory usually 4 glandular zones are distinguished in the
prostate. The correct interpretation of NLS data largely depends on the knowledge of
their topical pattern. 20% of the glandular tissue correspond to the central zone (CZ).
The peripheral zone (PZ) occupies 75%. The intermediate (transitory) zones (TZ) make up
5% of the total amount of the glandular tissue.
Perurethral galnds (PUG) take a relatively small amount of the tissue, however exactly this
area of the gland is very important for explaining the changes at a benign
hyperplasia.
Apart from the glandular area, 4 fibro muscular zones can be discriminated:
1. Anterior fibro muscular stoma (AFS).
2. Unstriated muscular fibers of the urethra (UMFU).
3. Preprostatic sphincter (PPS), which is an extension of the musculature of the inferior
part of the ureter and prevents inverse emission of seminal fluid.
304. Postprostatis sphincter (PPS), which is responsible for retaining urine in the bladder
and blocks incontinent micturition.
The gland can be conventionally subdividied into 2 parts: -
external part consisting of CZ, PZ, TZ and
- internal part comprising AFS, PPS and PoPS.
According to NLS-investigation, the external part looks like a structure of normal
chromogenic density (2-3 points of Flandler’s scale), and the internal one is
hypochromogenic (1-2 points). The two parts are divided by a fibro muscular layer, the so
called surgical capsule, along which an incision is made during surgical intervention, and
calcium salts deposit (calcium incrustration of the gland). In the NLS-investigation those
formations can well be seen as fairly hypochromogenic structures (3-4 points) of
different size.
The analysis of the prostatic gland image on the NLS virtual model is made according to the
following quantity and quality characteristics:
1. Size: from to back - 2-2.5 cm, across - 3-4.5 cm, from top to bottom - 2.5-4 cm;
2. Volume: up to 20 cm;
3. Symmetry. The urethra is the reference point.
If any pathological changes are detected in the NLS-graph it is recommended to: -
specify their exact location;
- perform histography of the pathological area and area of the tissue with a normal
structure.
It will be helpful for the case follow-ups. At a benign hyperplasia NLS enables detection of the
direction of the principal germination. In case of hyper-trophic transitory zones the gland
proliferates inwards. Though darkened lateral zones are formed (4-5 points on Flandler’s
scale), the nodes can still be always visualized. The trans-rectal NLS offers the most detailed
and authentic information.
Enlarged lateral lobes squeeze PZ and CZ causing their atrophy. With proliferation of the
para-urethral zones a massive fibro muscular PPS layer restricts their hyperplasia, so with
this kind of pathology the gland proliferates along the urethra forming a middle darkened
zone pushing back the bladder wall. Virtual scanning makes this pathology clearly
visible in longitudinal sections. At the beginning of the proliferation a relationship
between the internal and external glandular parts is disturbed. Apart from some
distinctions in the zones of principal proliferation, the clinical signs will be different as
well. In the case where a globe-shaped gland is formed (TZ proliferation) the gland is
chiefly hyper-chromogenic and the dysuric manifestations are minimal while with a
‘middle zone’ formed the gland is slightly darkened and dysuria appears to be frank.
Sphincter decompensation leads to the development or urinary incontinence and dilation
of the upper urinary tract followed by the atrophy of the cortical layer of kidneys, which
gradually adds to frequent urination, nycturia, reduced pressure of the urine or reduced
rate urination occurring in the initial phase of the disease.
31In case of a squeezed cervix of the bladder a NLZ-graph provides visual signs of an
infravesical obstruction that causes some morphological and functional changes in the
lower and upper urinary tracts. Specifically, in the initial phases of benign hyperplasia a
darkened wall in the bladder can be observed. Dark patches result from compensatory
hypertrophy of the detrusor.
These 3 phases of benign hyperplasia of the prostate can be distinguished depending on
the intensity of the changes:
1. hyperchromogenic denisty of the gland with no residual urine;
2. residual urine present;
3. all of the above-mentioned plus dilation of the upper urinary tract with the cortical
layer of kidneys involved in the process.
Diagnosis of acute prostatitis is made on the basis of histograms (similarity to the
reference standard process “prostatitis” D>0.425). Diagnosis should be done in
combination with dactylar rectal examination (painfulness during palpation) with clinic lab
data taken into account).
In the case of abscessed lesion a still higher hyperchromous area (6 points) is visible
against the general dark patch (4-5 points according to Flandler’s scale). Areas of frank
blackening correspond to necrotic changes. With an abscess in progress one can notice a
reduced infiltration of the tissue around the cavity with the dark patch gradually getting
lighter in the course of dynamic observation (up to 3-4 points). With adequate therapy
employed the post inflammatory cyst may fall into regression.
As can be seen from NLS-investigation, chronic prostatitis does not give a common
characteristic picture, however the morphological processes in different phases of the
disease are reflected in histograms. With a long-lasting disease the chromogenic density
tends to rise due to a post-inflammatory substitution for the glandular component and its
histograms. In the ‘organ preparations’ mode destructuring of the fibrous component
starts to predominate.
With an oncological pathology, analysis of the gland picture helps localize the process in
different projections and assess the extent of prevalence and involvement of adjacent organs.
The minimum size of tumor determinable by means of NLS-investigation is about 8-10 mm.
80% of the tumor nodes are presented by markedly hyperchromogenic structures (6 points
on Flandler’s scale).
Analysis of histograms of the nidi help differentiate an onco-process. The method’s
sensitivity becomes higher with both ‘elimination’ and ‘NLS-analysis’ modes in use.
Peripheral zones have first place as far as cancer incidence rate is concerned. They
constitute 70-80% of cases. Transitory zones (TZ) are affected in 10-20% and CZ in less
than 5% of cases. In transitory zones a tumor nidus should be looked for within 3-4 mm
from the capsule. In case of an oncological alertness the symmetry in the lobe affection
is assessed with respect to the sagittal axis and intensity of the black patch (4-5 points on
32Flandler’s scale), in the adjacent organs, especially seminal vesicles and bladder because in
25% of cases metastases occurs through the gland apex and seminiferous tracts.
Considering the fact that cancer often develops with some diffuse changes occurring in the
background, for example, with chronic prostatitis or adenomatosis, it is not always possible
to visualize newly formed cancerous areas. In such cases the results of PSA level definition
and digital rectal examination should be considered. The PSA level is defined considering
the patient’s age and gland volume.
Conclusions:
1. NLS-method enables diagnosis of most prostate diseases and being a screening
diagnosis method, it should be supplemented by biopsy, should any pathological
changes be detected.
2. The final diagnosis should be made on the basis of the clinic lab data and the results
of digital rectal examination in combination with biopsy only.