1966 Singewald

Notes on the article:

 Singewald M.L.

Another cause of low back pain: lipomata in the sacroiliac region

Trans Am Clin Climatol Assoc. 1966, 77:73-9. PubMed PMID: 4223124; PubMed Central PMCID: PMC2441105.


By Martin L. Singewald, M.D. From the Department of Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland. Baltimore.

A minor condition but…

Singewald starts saying…

“There is an old saying in the theatre, that there are no small parts, just small actors. To the patient with pain, there are no small diseases, just the pain”.

“The condition which I shall now describe is a minor one, but one which is capable of producing much pain. It is frequently OVERLOOKED in consideration of the causes of low back pain and I have been amazed that so many physicians are unaware of it”.

Singewald states in the summary that these “lipomata” (fat herniae) in the sacroiliac region have been described as another cause of low back pain. He says that it is not very common, but it is a benign cause, which is easy to diagnose by injection at the base of the “lipoma” with local anaesthetic, which produces immediate relief of pain and immediate mobility of the back. Treatment can be repeated injection or surgical removal of the fat herniae. The results of surgical removal are uniformly good.

The typical case history: a middle-aged woman

The typical case history is a middle-aged, obese female, who comes complaining of low back pain usually on one side with some radiation to the buttock and, occasionally, to the thigh. The duration has been fairly long (more than a year). She has seen many doctors (orthopaedist, neurologist…), and often since nothing specific has been found to cause her backache, they send her to the psychiatrist. On her own she has consulted chiropractors or osteopaths, all to no avail. The pain, at times, is more severe; at times, it disappears, only to return. The activity makes it worse and forward binding is painful. Even rolling over in bed at times produces severe pain or “ache”.

The neurological examination is normal. The main finding is a small tender nodule in the sacroiliac area, which feels like a lipoma. It is movable and very tender to pressure. There may be more than one. If infiltrated with local anaesthetic, tenderness and referred pain vanish. The back becomes mobile and diagnosis is confirmed.

The sacro-iliac “dimples” serve as starting point

The location of these lipomata is usually within 5 cm to the natural “dimple” in the sacroiliac area. This fact was pointed out in the very first work that Singewald uncovered, one paper by Dr. Emil Ries from Chicago.

Singewald is amazed that so many young physicians are unaware of the natural dimples and even never palpate this area on examination.

PERCENTAGES in normal population

Emil Ries examined 1,000 people, and of these, one-third had nodules present, and of this group one-third had backache or some similar pain. Copeman estimated that 10% of normal persons had these fat nodules.

By Singewald experience, 16% of the patients he examined had these nodules, and 10% of these were symptomatic.

 The small nodules radiate the pain

The small lipomata can radiate the pain considering the work of Kellgren, who while working in the laboratory of Sir Thomas Lewis, used a series of experiments to show that pain nerves of the skin belong to a system separate from those belonging to deep lying structures.

Kellgren found, by injecting saline solution, that fasciae pain was referred to the neighbourhood of the injection, whereas pain from the muscles is felt diffusely and is referred down. Deep pain sensibility can be distinguished clearly from cutaneous pain.

The work of Copeman, the fat hernia

Singewald reviews the work of Copeman published in 1944 “Fibrositis of the back”. He explains that Copeman demonstrated that the fat nodules could be fat hernia between the fascias. Copeman divided the fat hernia into three types: non-pedunculated type, pedunculated, and foraminal. He also mentions the work of other authors (mainly surgeons): MacDermot 1942, Hucherson 1948, Hittner 1948, Dittrich 1950, Bonner 1954, Raymond 1960, and Wollgast 1961.

Singewald: 53 cases, mainly surgical cases

-They were collected from several hospitals

-20 from the records of the Johns Hopkins Hospital

-9 from Union Memorial Hospital, Baltimore

-2 cases of the Church Home and Hospital, Baltimore

-22 cases from his private practice, all symptomatic, 6 of who came to surgery.

-Age and sex range: age from 16 to 82, females 4:1.

-2 cases required a second operation.

-2 cases had previously been operated on for herniated disc and still had back pain following the disc surgery.

-Injections with xylocaine at the base of the fatty nodule often produced lasting relief from the pain.

-Occasionally, the establishment of the diagnosis relieves the patient of the fear of some serious musculo-skeletal disease and enables the person to tolerate better the symptoms.


-Dr. K. J. R. Wightman (from Toronto) asked Dr. Singewald about the treatment with very heavy local massage to this lipoma herniation that can occur in the border of the scapula. Singewald comments that the heavy massage sometimes can work and sometimes made them much worse and created an acute problem.

-Dr. William B. Bean (from Iowa City) asked Dr. Singewald if he knew the exact mechanism of pain producing of these fat hernias. Both agreed it could be entrapment, torsion, or ischemia. And it also could have a relation with the pain of Dercum’s disease.

Published in March 2018

By Marta Cañis Parera


  • Singewald ML. Another cause of low back pain: lipomata in the sacroiliac region. Trans Am Clin Climatol Assoc. 1966;77:73-9. PubMed PMID: 4223124; PubMed Central PMCID: PMC2441105.
  • Reis E. Episacroiliac lipoma. Am J Obstet Gynecol 1937;34:492-8.
  • Copeman WSC. Fibro-fatty Tissue and its Relation to “Rheumatic” Syndromes. British Medical Journal. 1949;2(4620):191-197.
  • HERZ R. Herniation of subfascial fat as a cause of low back pain; report of 37 cases treated surgically. Ann Rheum Dis. 1946 Dec;5(6):201-3. PubMed PMID: 20242353.
  • MAcDERMOT, J. H.: Sacro-iliac Lipomata. Bulletin of the Vancouver Medical Association,18: 185,1942.


By Marta Cañis Parera   ORCID iD icon