This long article (15 pages) about the sinddromi lombo-sciatalgishe or lumbosciatic syndrome was published in 1952 (what I called “the golden ages of back mice”), probably after the influence of Copeman’s research. It was published by two surgeons from the “Univertsità di Pavia” in Italy.
They present 5 observations of patients with sindromi lombo-sciatalgische and lombo-sacralgiche [lumbo-sciatalgic and lumbo-sacralgic syndrome].
They present an extensive bibliography and an interesting review from the literature.
Donati and Bidoni present black and white pictures of 3 of the episacral lipomas or back mice that they removed from patients.
And they describe them histologically as a lipoma with a bright fibrous capsule in the deep subcutaneous planes.
Mainly, they removed unilateral lipomas. In one case it was bilateral. One of the cases (case 4) was a big lipoma of 12x7x5. The lipomas were easily enucleated.
The macroscopic aspect was of a POLILOBULATED fibro-fatty MASS, sometimes with a BRIGHT CAPSULE that suggested EDEMA phenomena. Microscopically, it was of a normal fatty tissue. Sometimes nerve fibrils were present.
All cases were WOMEN.
In case 5 there were signs of hepatic insufficiency.
In 4 of the 5 patients, the low back pain presented as a sindromi lombo-sciatalgiche [lumbosciatic syndrome]
In some cases, the Lasègue sign was positive.
Notes on the article:
Lipomi della regione sacroiliaca (episacroiliaci) come causa de sindromi lombo-sciatalgiche e di lombo-sacralgiche
[Lipomas from the sacroiliac region (episacroiliac) as a cause of the lumbosciatic syndrome]
By Prof. G.S. Donati and E. Bidoni
Instituto di Patologia Sceciale Chirurgica e propedeutica clinica dell‘Università di Pavia
The introduction about sindromi lombo-sciatalgiche
Donati and Bidoni start the article by saying that, in recent times, there has been interest and attention to certain cases of sindromi lombo-sciatalgiche [lumbosciatic syndrome] that present in the sacro-iliac region a modest sized lipoma, that if removed, makes the disappearance of the painful syndrome.
They prefer to call them L.E.S.I. (Lipome Epi-Sacro-iliaci).
They consider that these LESIs (or back mice) haven‘t been adequately evaluated.
They mention the work of Ries (1937) as the first one to be intrigued by the LESIs and published about them 317 cases of lipomas from 1,000 patients with lumbosciatic syndrome. Also Hittner published about 50 cases of them in 1949. It is difficult to say what its prevalence is, but Donati and Bidoni think that it is not a rare cause.
The entity, according to Ries and Hittner’s work, suggests that it is a common finding in adult life, around the 40s.
The L.E.S.I., when studied macroscopically and microscopically, present as a LIPOMA in a PECULIAR zone: in the sacro-iliac and lumbar region at the surface of the sacroiliac joint that is why they are called sacroiliac lipoma by some authors.
Mainly they look like MULTILOBULATED or arborescent masses, other times they present as round masses that are the size of a hazelnut or a plum.
Sometimes they present unilaterally but mainly bilaterally and, especially, SIMMETRICALLY. Sometimes they are MULTIPLE (then usually one is more voluminous than the others).
Ries published even subjects with 4-6 lipomas (back mice).
Donati and Bidoni summarize that, clearly, the sacroiliac lipomas present the characteristics of DUPLICITY, BILATERALITY AND SYMMETRY (Ries published 213/317 bilateral, and Hittner 35/50).
The surface is mostly smooth and sometimes there are “fibrous lacerations” or fibrous tissue that somehow fixes the lipoma (back mice) on the deeper layers. Sometimes it seems that the lipoma connects with deeper fatty layers throughout the lumbosacral fascia resembling an hernia.
They have the consistency of a lipoma, however they present an elastic consistency or hard also, due to edema or connective tissue proliferation.
The nodules or masses can present a well DEFINED CAPSULE, which is usually very faint.
“Questa può formare una vera e propia capsula ben delineata, capsula chè però di solito è molto tenue.”
They move more along the TRANSVERSE plane than the LONGITUDINAL plane, but sometimes they are completed fixed along the underlying layers.
These lipomas can be asymptomatic or painful spontaneously or on palpation. Sometimes they present pain exquisitely on palpation.
The fact that they can be exquisitely painful on palpation is useful for the diagnostic.
Histologically, some authors found nerve fibrils and they described them as a kind of neurolipoma, but most of the histologic studies did not resolve these findings.
Copeman and Pugh noticed that some of the lipomas presented tension due to edema within a capsule. They studied the difference between the “silent” lipomas and the painful ones and could conclude that the painful ones would be tenser due to edema within the capsule.
Notes about the etiopathogeny of the sindromi lombo-sciatalgiche
First of all, Donati and Bidoni gave importance to the fact that the l.e.s.i. (back mice) appear predominantly in the female sex, obese women and in the menopausal ages, which coincides with the endocrinal disturbances.
Campiglio relates the etiology with a feminine dysfunction related to feminine sex organs.
A. Blanch related to the protein metabolism and calls it LIPOSCLEROSI DISPROTIDEMICHE.
Donati and Bidoni comment that the women seem to have a major presence of adipose tissue in the sacroiliac region, more noticeable than in men, where the l.e.s.i arise.
Some have related the presence of the l.e.s.i in that zone due to the MICROTRAUMAS, which that region can suffer by continuous or repeated trauma.
The pain is related to the irritation of the LUMBAR POSTERIOR BRANCHES of the lumbar nerves (also called now cluneal nerves). The pain refers to the abdomen or the lateral thigh without reaching the knee.
Copeman had the theory that the pain was due to the edema in the adipose tissue by a kind of VASOMOTOR disturbance as a consequence of alterations of the normal mechanism of water absorption, and the adipose tissue gets distended and turgid, producing local compression.
Ackerman states that the appearance of the nodules or the fibrolipomatouse masses is related to the fact that the FAT LOBULES are subjected to a continuous and frequent traumatism in the sacroiliac region. The lobule then would “escape” from its place with the capsule through an aponeurotic hole or stretch from the fibrous wall.
CLINICAL PICTURE OF THE sindromi lombo-sciatalgiche by L.E.S.I (back mice)
Donati and Bidoni believed that it was opportune to distinguish clinically:
- asymptomatic forms
- lombosciatalgic forms
- lombosacralgic forms
The asymptomatic forms are not painful neither spontaneous or on palpation.
The lumbosciatalgic and lumbosacralgic can also coexist in some patients.
The American authors denominated it “lipoma low back”.
The pain can present in different forms and can be so acute that can be very incapacitating.
Donati and Bidoni warn that the decubitus not always provokes the same effect. Some patients feel relief; others feel more pain (maybe due to pressure on the lipoma formations due to the body weight).
Sometimes there can be a certain degree of hypotrophy of the affected limb.
The pain is usually worst in one side, and can radiate to the loins or to the gluteal region, or in a sciatic form.
The Lasègue sign is often absent and the reflexes are usually normal.
An important clinical sign is that, by palpation, the patient can experience a referred pain, thus being provokable especially when the patient is in dorsal decubitus.
The painful syndrome can last for years.
Many of the patients ignore the presence of the episacroiliac tumefaction and are not able to tell precisely the onset of the pain or the lumbosciatic syndrome.
DIAGNOSIS OF THE lumbosciatic syndrome by L.E.S.I (back mice)
The differential diagnosis has to be taken in consideration.
Donati and Bidoni mention other names of published pathologies:
“Per esempio le miositi, le celluliti, le steatopigi dolorose, igromí e fibrositi delle masse lombo-sacrali, psoiti, granulomi da corpo estraneo….” (a long list).
They also warn that the L.E.S.I can COEXIST with other pathological entities.
Then it is very useful to inject 2% NOVOCAINE within the lipomas themselves. If the pain disappears, then it means that the lipomas are the cause of the pain.
PROGNOSIS of the lumbosciatic syndrome by L.E.S.I
It can vary form a silent form to long-term pain. It can also undergo a certain degree of inflammatory changes as fibrosis.
THERAPY of the lumbosciatic syndrome by L.E.S.I
Donati and Bidoni start saying that the novocaine injections would just represent a diagnostic tool, but the healing would have to be the surgical removal. In obese patients maybe general anesthesia would be necessary.
The lipoma had to be completely removed and the cavity must be reduced by suture. Drainage may be placed. In most of the cases the patients improved.
Copeman stated that just the intranodular novocaine injection with the intention of stretching and LACERATING the fat could also be curative in certain cases.
Donati and Bidoni present 5 observations.
Observation 1: A 24-year-old patient
Two years before she noticed a tumefaction in the sacro-iliac region of a “cherry” size. In the last weeks she noticed pain in low back that referred to the posterior face of the right thigh and also the knee. The pain disappears with rest but got worst with decubitus supinus. The patient was operated by Donati. First, they performed a novocainic local anesthesia. They performed a LONGITUDINAL incision. Then they reach:
“Si arriva sulla tumefazione che appare costituita da tessuto adiposo rachiuso in una loggia seavata attraverso l’aponeurosi e delimitata in profundità del piano osetolegamentoso”
The surgical diagnosis described: “Lipoma della regione sacro-iliaca di destra” The size was 2x2x4. Ovoid shape. WITH A FIBROUS CAPSULE “lucente”. Hard fibrous consistency. It had a LOBULATED appearance with yellow tissue and fibrous connective tissue. Histologically it shows the signs of a lipoma, with fatty cells with abundant connective tissue.
Observation 2: A 32-year-old patient. Nodule in the gluteal region and sacroiliac region. Pain in lower back. The nodule was removed easily surgically. With the diagnose of LIPOMA DE LA SACRO-ILIAC REGION. Shape 8x5x6. With a capsule. Yellowish. Irregular LOBULATION. The patient CURED after surgical removal as far as 3 months later.
Observation 3: A 24-year-old patient. Surgical removal of a multiple lipoma meant curation.
Observation 4: A 41-year-old patient
Macroscopic examination:
“Il pezzo asportato si presenta de forma grossolanamente ovoidale con il maggior asse di centimitri 12: di colorito giallastro, superficie bozzuta, bernoccoluta, ricoperta per buona parte da una capsula sottile, velamentosa, lucente e nel restante da lacinie fibrose: consistenza molle anelastica in alcuni punti, duro-parenchimatosa in altri”
The patient cured after surgical removal.
Observation 5: A 47-year-old patient. Sacro-iliac pain for 4 months. BILATERAL SACROILIAC LIPOMA. Shape 6x3x2. Yellow-gray colour. Bright capsule.
Dibuix referencies
Published in March 2019 By Marta Cañis Parera 
Article‘s reference:
Donati G.S. Bidone E. Lipomi della regione sacroiliaca (episacro-iliaci) come causa de sindromi lombo-sciatalgiche e di lombo-sacralgiche. La Clinica ortopedica. 1952 4 p427-442. ISSN/ISBN: 0009/9023.
