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.