The pelvic lipoma is a rare disease, related to the abnormal and excessive development of fat tissue in périvésical and périrectal areas. If it is well established that there is not histological character of malignancy, it does not remain less true about it than the spontaneous evolution of this disease can be serious because of compression périurétérale and périrectale which requires corrective surgery.
The etiology of this disease is unknown, as is its medical treatment.
In 1959, ENGELS presents 5 observations of compression of the pelvic bodies by a fat proliferation. He describes the characteristic radiographic images.
In 1968, FOGS and SMITH propose the term of pelvic lipoma currently used, to describe the abnormal development of fat tissue in the périvésical and périrectal areas occurring, thought, exclusively in men of black race.
Since these time, many publications (more than 100) came to confirm the reality of this particular disease but its racial prevalence disappeared. It is found in the United States in both white and blacks, in North Africa and Europe. To date, no case has been reported in Asia.
Recently, tomodensitometric descriptions brought a support fundamental diagnosis.
ANALYZE SYNTHETIQUE OF THE PELVIC LIPOMA
Initially described in men of black race this affection touches, actually, all the races (although no publication was reported at the Asian ones). The women are exceptionally touched (4 cases were published until now).
The average age is 40.9 years, the extreme ones going from 9 years (MOSS) to 80 years.
There are no clinical signs characteristic of this disease; only indirect signs testify to the fat proliferation.
1) Urinary signs
In general, they dominate the clinical table (75 % of the cases). They are:
- repeating cystitides, generally with colon bacilli
- pollakiurie diurnal and night
- pressing micturitions
- more rarely of dysurie
- the hématurie is frequent, microscopic especially, sometimes macroscopic, total or final accompanying the signs by cystitides,
- the lumbar pains are rarer, present in 20 at 30 % of the cases. They are either true renal colics, or of deaf, permanent pains lumbar, due to the dilation of the renal cavities,
- the renal insufficiency is seldom a reason for consultation but can be found at the time of the biological assessment.
2) Digestive signs
They are sometimes in the foreground (60 %). It acts of:
- obstinate constipation being able to lead to a low occlusion
- abdominal pains
- hémorroïdes external or interns associated with rectorragies.
3) Other revealing signs
They are much rarer; however, the phlebites with repetition are not exceptional (3 to 5 %).
Thus, the revealing signs do not have anything specific. They translate vesical irritation and the compression of the rectosigmoïde and the uretères.
4) The clinical examination
It can discover two revealing anomalies:
- at the time of the rectal examination one discovers a heightening of the prostato-vesical block which is included in a regular mass, soft, extending to the pelvic walls,
- at the time of abdominal palpation, one perceives a know-pubic mass soft, painless, that is to say with the fat proliferation
- as for the discovery of subcutaneous fatty nodules, it is exceptional and is integrated within the framework of a disease of DERCUM
- the general state is well preserved; there is no slimming nor of fever. Obesity, sometimes described, is in fact exceptional.
They do not have anything specific and cannot thus direct the diagnosis.
- There is often an inflammatory syndrome with a sedimentation test which does not exceed 30 to 40 per 1st hour.
- the blood ionogramme, the immunological examinations, the test hepatic are all normal.
- the examination of the urines, however, can reveal a urinary infection with germs banals, a pyurie amicrobienne, a microscopic hématurie.
- Lastly, in the event of major dilation of the renal cavities one can see occurring a renal insufficiency.
They are on the other hand very evocative:
- the uretrocystoscopy shows in all the cases a very significant lengthening of the posterior urethra which rigid, is fixed, stretched, with a clear heightening of the vesical floor, with such sign that frequently the cystoscope proves too short to penetrate in the bladder.
When the endoscopic examination of the bladder is possible, this one appears often red, inflammatory, with in 75% of the cases, the signs of cystitides glandular or cystic. Sometimes, there are inflammatory pseudotumeurs.
- the rectoscopy discovers signs of extrinsic compression of the rectum and rectosigmoïde; there is sometimes a sténose such as the passage of the rectoscope is impossible. On the other hand, the digestive mucous membrane is normal. The presence of hémorroïdes external and interns testify to the venous damning up due to the fat proliferation périrectale.
They are fundamental because they make it possible to make the diagnosis.
1) The intravenous urography
It shows two commands of signs:
- direct signs: the bladder median, is raised, deformed in drop of water, is pyriforme; its walls are brought back towards the centre line; there is not, in rule, of residue postmictionnel. The pelvic uretères are driven back towards the centre line, sometimes sténosés on the level of their vesical penetration. The posterior urethra is rolled. When soft rays are used, one discovers a clearness, périvésicale with visualization of the shade of the obturating muscle which is detached on this clearness.
- indirect signs: it is primarily about urétéro-pyélocalicielle dilation. The uretères are more or less dilated but always sinuous, testifying to the chronic pelvic obstacle and the progressiveness of compression.
2) The baryté rectal injection
It is him also characteristic:
- the rectum narrow, is lengthened; the hinge rectosigmoïdienne is generally interested by extrinsic compression. The handle sigmoïdienne is driven back upwards and dilated. The stereotypes with soft rays reveal one there too hyperclarté pelvic very characteristic.
When the opacifications colorectales and vesical are carried out at the same time, appears a widening of the inter-vésico-rectal space which is filled by a tissue to hyperclair.
ON THE WHOLE, bladder suspended, pyriforme, uretères pelvic attracted towards the centre line, uretères lumbar and renal cavities dilated, lengthened posterior urethra, stretched, rolled, sigmoid rectum upwards driven back, widened inter-vésico-rectal space, all these deformations " bathing " in an atmosphere hyperclaire. There is thus an expansive process to hyperclair involving a compression of the pelvic bodies.
3) The tomodensitometry
This examination became essential to carry the precise diagnosis of pelvic lipoma:
- space périrectal is occupied by tissue hypodense, radiotransparent, regularly distributed. This engainement in the shape of sleeve goes up to the headland. The distance between the rectal light and the crowned vertebrae is increased,
- the tissue hypodense extends ahead towards the block vésico-prostate sufferer, the posterior face and the side faces of the bladder,
- finally, the density of this tissue to the scanner is characteristic, it is that of fat tissue.
The other complementary examinations do not bring any diagnostic element:
a) The arteriography
It could show a very moderate hypervascularisation of pelvic spaces.
It is, in general, normal; however, two observations of thrombosis of the vena cava were reported.
It shows ganglionic groups normal but driven back towards outside.
d) Pelvic echography
It reveals the existence of a more or less echoic mass near to fat tissue.
The fat panicle parietal is normal.
With the opening of the peritoneum, which it is necessary to make close to the umbilical point, the small basin appears filled by fatty tissue distributed around the bodies and extending to the walls.
The bladder is driven back to the top, out of the pelvis. It goes up to the umbilical point. Its wall is thick. The cul-de-sac the DOUGLAS one is completely filled by fat. The rectum is rolled.
Palpation does not make it possible to discover any tumoral mass. The peritoneum visceral and parietal is smooth, shining, without hypervascularisation. When it is opened, fat appears hypervascularized, but of normal consistency.
The abdominal bodies are normal. The mésentère, in particular, does not present fat proliferation.
The proliferation consists of mature fatty lobules, with a moderate hypervascularisation. There is not any malignant cell.
There exists, by places, of the fibrous spans in small quantity. Inflammatory cells are sometimes met.
The histological hardware is obtained either by biopsies peropératoires, or by percutaneous punctures with the fine needle.
CARPENTER, since 1973, considers two evolutionary methods:
1) The evolution becomes complicated inflammatory phenomena
The vesical signs frequently repeat; the constipation progresses. The fibrose would replace the lipoma gradually. In these forms, two complications occur:
- the acute obstruction of the bowels requiring a digestive derivation,
- the renal insufficiency by compression resulting in death if a urinary derivation is not carried out. This evolutionary form would be the prerogative of the young men.
It is in these forms that some could consider the possibility of a malignant degeneration of vesical tissue. JOHNSTON in 1980, published the only observation of vesical adenocarcinomist which has occurred at a patient having an obvious pelvic lipoma. He thinks, after this observation, that the pelvic lipoma can have a malignant potential, or, in any case, to support the malignant degeneration of the lesions of glandular cystitis frequently met at the time of this affection.
2) The on the other hand, the evolution remains sometimes asymptomatic
The extrinsic compression of the colonist does not progress, dilation urétérale is moderated and does not evolve/move, the clinical signs are non-existent. These forms of fortuitous discovery would be the prerogative of the old men (more than 60 years).
ON THE WHOLE:
1) MEN YOUNG < 55 YEARS
DANGER: 50 % OF DERIVATIONS
2) MEN AGES > 55 YEARS
LITTLE DANGER: 6 % OF DERIVATIONS
RELATIONSHIP TO THE OTHER ANOMALIES
DISTRIBUTION OF FATS
In the literature, one finds few obvious associations with other hereditary or acquired diseases distribution of fats.
1) The syndrome of DERCUM
Exceptionally, the pelvic lipoma could be integrated in a syndrome of DERCUM (4 cases). It is about an affection characterized by the presence of painful fat masses laid out on the trunk and the members, by obesity, sensitive and psychic disorders; the evolution is fatal and of unknown origin. Sometimes, hormonal disorders are discovered (thyroid and pituitary gland).
2) Lubricating degeneration of lymphatic (hypoplastic pelvic lymphadenopathy)
It is about a very rare affection (2 cases in 1975 less than 10 cases in 1983). The lymphatic ganglia are invaded gradually by mature fatty tissue, without any sign of malignity.
On the level of the small basin, the ganglia are bulky and at the origin of an extrinsic compression of the pelvic bodies. Some could think that it was about a lubricating metaplasy of the ganglia in response to chronic infections. If, locally, the radiographic signs make think of a pelvic lipoma, the dissemination of the ganglionic attacks and the images very abnormal with the lymphography, separate the two affections very clearly.
If MANNING, in 1975, considered a relationship between the pelvic lipoma and the lubricating degeneration, currently this relationship more than is questioned.
3) The lipoma of the renal sine
It is about the proliferation of a fat and fibrous tissue in the renal sine with few inflammatory phenomena. Admittedly, symptomatology and the localization have nothing to do with the pelvic lipoma, but this proliferation could be due it also to repeated infectious phenomena.
4) Other lubricating decays
Decays, the such disease of WHIPPLE, very have like common point a long past of repeated infections.
5) Relation with the fibrose rétropéritonéale
Some wanted to see an analogy between the pelvic lipoma and the fibrose rétropéritonéale. For WEMEAU and MAZEMAN, taking again the ideas of FOSS and SMYTH, the analogy is obvious and these authors go until affirming that the fibrose rétropéritonéale would be only the result of the lipoma.
Admittedly, these two affections have common points:
- evolution sometimes similar as well at the urinary level as at the digestive level,
- presence in both cases of close histological lesions with inflammatory elements and fibrous elements.
Actually, of many differences exist:
- in the event of lipoma, never no toxic etiology was found,
- the localizations are very different,
- the vascular examinations, in the fibrose rétropéritonéale, are very evocative as opposed to what one can see in the lipoma where they are, in rule, normal.
It seems now acquired that these two affections are well separated, without any relation one with the other.
The lubricating degeneration or the lubricating metaplasy being a possible response to a chronic infection, some wanted to regard the pelvic lipoma as the consequence of a microbial aggression, integrating it within the framework of the lubricating métaplasies.
That said, if one cannot reject this assumption completely, one should consider it only with caution. Indeed, whereas they are the women who are generally prone to the pelvic infections, only, or almost, the men are reached by the pelvic lipoma. To explain this difference, BRISSET plans either a chronic of seminal origin or prostatic infection, or still the dominating role of the male hormone.
In fact, one has no proof, no beginning of explanation, but only of the assumptions.
As of the discovery of the pelvic lipoma, arose the difficulty to eliminate the other causes from tumour or of invasion of the pelvis and the surgical browsing with biopsic aiming proved to be essential. Currently, this affection being rather well described, in particular thanks to the scanner, it is possible to affirm the diagnosis without having of it to resort to histological confirmations.
However, a differential diagnosis must be isolated: the cancer of the prostate in its " rectal " form.
Two different tables can be seen:
- cancer is very advanced, it blocks the small basin; the prostate is embedded in a hard, irregular tissue. The disorders mictionnels are in the foreground.
- the rectum is rolled, compressed by the tumoral extension. The clinical examinations and paraclinic simple are enough to carry the diagnosis... which besides is often known since years.
Cancer does not involve any vesical sign but on the other hand digestive disorders (diarrhoea, glaires...). The rectal examination is not very significant, the prostate seems relatively normal. Only its base is irregular and seems to be prolonged in a firm and diffuse atmosphere. On the intravenous urography the bladder is elevated. On the baryté rectal injection, the rectum is rolled, driven back.
Two examinations are essential:
- urinary smears
- the biopsy prostate sufferer.
Other diagnoses are sometimes more difficult to draw aside:
- the malignant lymphosarcome limited to the pelvis
- the liposarcome rétrovésical (3 cases in 1980).
There still, the clinical examination discovers a mass which should be punctured and the scanner eliminates a pelvic lipoma. In case of doubt, the laparotomy with biopsies makes it possible to take a decision.
On the other hand, it is easy to eliminate:
- pelvic lymphatic metastases
- vascular disorders such as the pelvic varixes of hollow thromboses
- a pelvic hématome under péritonéal.
ON THE WHOLE, it is necessary to retain the interest:
- clinical examination
who allow to avoid the exploring laparotomy.
TREATMENT OF THE PELVIC LIPOMA
The pathology of this affection is unknown. Its evolution is different according to patients'. It is enough to underline the difficulties of a treatment which remains discussed.
1) Medical treatment
It primarily calls upon corticoids with the amount from 40 to 60 mg/jour of Cortancyl during several months. Of course, it is necessary to ensure a strict monitoring of the effects by the urography and the examinations biological during, and especially after the stop of the treatment.
This treatment is sometimes remarkably effective, primarily when the inflammatory signs are in the foreground. However, a certain number of cases repeat with the stop of the treatment.
Auxiliary treatment: it is essential to treat a urinary infection by a antibiotic therapy with the long course. The type of antibiotic does not seem fundamental although some recommend the use of the tétracyclines. The radiotherapy was tried in rare cases. It seems not to involve any beneficial effect.
2) Surgical treatment
The purpose of the surgical treatment, when it is indicated, is not to withdraw the lubricating proliferation but to restore a digestive function and a renal function, when those are threatened.
Restoration of the digestive function:
the pelvic lubricating proliferation can involve a compression rectosigmoïdienne and lead to an occlusion; the only possible treatment is then the derivation of the matters by a colostomy. This derivation is sometimes temporary if the medical treatment by corticoids involves a significant reduction in pelvic compression. It is final in the event of failure of the medical treatment.
Restoration of the renal function:
sometimes, urétéro-pyélocalicielle dilation is such as she threatens the renal function seriously and obliges with a gesture of derivation in urgency. This gesture must make it possible to expect the possible effects of the medical treatment. It can be a question of a percutaneous pyelostomy or a surgical pyelostomy. The cutaneous ureterostomy from the start is to be proscribed because it is very invalidating and practically irreversible.
But dilation is not, not always immediately threatening what can leave time to begin the medical treatment; however, if this last does not prove sufficiently effective, final derivation is essential.
Three methods were used:
- the bilateral cutaneous ureterostomy but one knows his discomfort and its risks
- cutaneous derivation transiléale (Intervention of BRICKER) whose long-term risks are less but which, despite everything, lets persist an external derivation,
- urétéro-vesical reimplantation out of the small basin. The first direct urétéro-vesical attempts at reimplantation apparently were of the failures because the thickness of the vesical wall; if this process nevertheless were chosen, any technique of establishment with a system antireflux seems to have to be avoided. On the other hand, the urétéro-vesical establishment by the intermediary of a conduit iléal seems tolerated better and not to involve a later sténose.
The pelvic lipoma remains a not very frequent affection even if, currently, it is of relatively easy diagnosis.
Although its origin is completely unknown, its treatment seems to profit in a spectacular way of corticoids. In spite of that, the disease remains serious since, in 50 % of the cases, it will oblige to resort to a derivation either colic, or urinary. Lastly, it seems that final urinary derivation best tolerated either urétéro-vesical reimplantation transiléale.