spinal epidural lipomatosis ( sel ) is a disorder defined as having pathological overgrowth of normal extradural fat , which can compress the spinal canal or nerve root . it has been regarded as a consequence of long - term administration of exogenous steroids , associated with a variety of glucocorticoid - producing systemic diseases9 ) . several literatures , in western population , including retrospective reports on sel have been analyzed with respect to disease etiology , gender , age , bmi , involved segments , treatment methods and their outcome . until now , however , no reviewed article ever dealt with koreans except for sporadic case reports . the sel characteristics of koreans and westerners were reviewed and compared to the following scrutiny of those reported cases studies , including three cases for this report . a 43-year - old male without any underlying illness , suffered a neurologic deficit and neurogenic intermittent claudication ( nic ) of his lower legs , which were precipitated by ambulating a distance longer than 100 meters . lumbar mri on t2-weighted image ( t2wi ) implicated that the fatty lesion extended from the posterior aspect of l1 body to the body of s1 ( fig . the axial image revealed the typical " y - sign " or " stellate - sign " of the thecal sac ( fig . multi - level small laminotomy was performed on the left side of l1 , l2 , l3 , l4 , and l5 , while bilateral decompression was carried out with a one - side approach ( fig . postoperative mri revealed a much reduced epidural fat and decreased compression of the sacral sac ( fig . six months after follow - up , he was free from the symptoms . a 58-year - old male had a sustained lower back pain , leg fatigue and weakness , showing neurogenic intermittent claudication ( nic ) . the sagittal and axial t2wi mr images showed an extensive epidural fat deposition with a thecal compression from l1 to l5-like thread beads on the string ( fig . concomitant l4 - 5 spinal stenosis , due to a protruded disc and ligamentum flavum hypertrophy , was also seen . right l3 hemipartial laminectomy and l4 total laminectomy with the interbody fusion on l4 - 5 were performed for the treatment of underlying spinal stenosis ( fig . postoperative mri revealed much reduced epidural fat with decompression of the thecal sac ( fig . after the operation , the patient improved immediately and one year after follow - up . a 69-year - old male with diabetes mellitus , hypertension , and chronic renal disease , had a longstanding radiating pain , and showed symptoms of nic predominantly in the anterior aspect of the right knee . this patient had numbness in the sensory dermatomal distribution of l4 in the right leg . the lumbar mri revealed moderately bulged intervertebral discs at l4 - 5 and abnormal hypertrophy of the adipose tissue on the posterior aspect of the spinal canal extending from l3 to l5 . it was especially shown in the anterior aspect of the body of right l4 , which revealed compression on the dural sac and right l4 nerve root ( fig . right l4 hemi - laminectomy , l4 - 5 discectomy and debulking of the epidural fat , especially on the right anterior aspect of the l4 body ( fig . the postoperative mri revealed a greatly reduced epidural fat , distinctive visualization of the decompressed sacral sac , and l4 root ( fig . a 43-year - old male without any underlying illness , suffered a neurologic deficit and neurogenic intermittent claudication ( nic ) of his lower legs , which were precipitated by ambulating a distance longer than 100 meters . lumbar mri on t2-weighted image ( t2wi ) implicated that the fatty lesion extended from the posterior aspect of l1 body to the body of s1 ( fig . the axial image revealed the typical " y - sign " or " stellate - sign " of the thecal sac ( fig . multi - level small laminotomy was performed on the left side of l1 , l2 , l3 , l4 , and l5 , while bilateral decompression was carried out with a one - side approach ( fig . postoperative mri revealed a much reduced epidural fat and decreased compression of the sacral sac ( fig . a 58-year - old male had a sustained lower back pain , leg fatigue and weakness , showing neurogenic intermittent claudication ( nic ) . the sagittal and axial t2wi mr images showed an extensive epidural fat deposition with a thecal compression from l1 to l5-like thread beads on the string ( fig . concomitant l4 - 5 spinal stenosis , due to a protruded disc and ligamentum flavum hypertrophy , was also seen . right l3 hemipartial laminectomy and l4 total laminectomy with the interbody fusion on l4 - 5 were performed for the treatment of underlying spinal stenosis ( fig . postoperative mri revealed much reduced epidural fat with decompression of the thecal sac ( fig . after the operation , the patient improved immediately and one year after follow - up . a 69-year - old male with diabetes mellitus , hypertension , and chronic renal disease , had a longstanding radiating pain , and showed symptoms of nic predominantly in the anterior aspect of the right knee . this patient had numbness in the sensory dermatomal distribution of l4 in the right leg . the lumbar mri revealed moderately bulged intervertebral discs at l4 - 5 and abnormal hypertrophy of the adipose tissue on the posterior aspect of the spinal canal extending from l3 to l5 . it was especially shown in the anterior aspect of the body of right l4 , which revealed compression on the dural sac and right l4 nerve root ( fig . right l4 hemi - laminectomy , l4 - 5 discectomy and debulking of the epidural fat , especially on the right anterior aspect of the l4 body ( fig . the postoperative mri revealed a greatly reduced epidural fat , distinctive visualization of the decompressed sacral sac , and l4 root ( fig . lee et al.20 ) in 1975 first described sel that developed in a patient who had a renal transplantation . sel is a rare disease , which may occur after long - term steroid administration for the treatment of organ transplantation , dermatomyositis , systemic lupus erythematosus , nephrotic syndrome , asthma , sarcoidosis , rheumatoid arthritis or crohn 's disease , or by systemic disease or endocrinopathies producing excessive endogenous corticosteroid1,16,20 ) . badami et al.2 ) in 1982 first reported idiopathic sel , associated with a symptomatic deposition of spinal epidural fat without any history of exogenous steroid administration or endogenous corticosteroid producing endocrinopathies as described above . haddad , et al.10 ) first hypothesized that idiopathic sel was caused by obesity only without steroid association . a significant number of patients with idiopathic sel in the literature were males , and more than 75% of all reported patients were obese26 ) . surgery may be necessary for patients who failed in weight reduction merely to improve the symptoms or for patients with intractable clinical manifestations . so far , according to the paper , the steroid associated cases commonly occurred in thoracic segments , whereas idiopathic cases were usually found in the lumbar segments1,9,13 ) . kawai et al.13 ) review of 30 idiopathic sel cases showed that this disorder had a strong tendency of male - predominance , and that only 3 of these cases were females . obesity was observed in most patients and only 4 patients were of normal body weight . al - khawaja et al.1 ) in 2008 published another review article of sel with 111 patients where 69 were relevant to steroids , while the remaining 42 were not . male gender was predominant in both idiopathic sel and secondary sel groups , taking up 80% and 70% , respectively . 65% of idiopathic sel occurred in the lumbar segments , whereas 73% of secondary sel occurred in the thoracic segments . they classified sel into four categories : the exogenous steroid use , 55.3% ; obesity only , 24.5% ; the endocriopathy or endogenous steroid group , 3.2% ; and the non - obese idiopathic group with approximately , 17% . according to their review , thoracic involvement was associated with the steroid - administered group , while the idiopathic sel group was found to involve the lumbar segment predominantly9 ) . medical journal search engines such as koreamed , km base , and pubmed were utilized to find published articles of sel associated with the korean ethnicity . kim et al.16 ) in 1986 first reported a case of sel that a korean patient with adrenocortical adenoma had developed . three ( 3 ) cases of this report and 29 already - published cases of korean sel patients were carefully examined and analyzed23 ) . idiopathic sel is defined as a rare disorder that causes spinal cord compression and neurological deficits without any evidence of exogenous steroid administration , endogenous cushing 's syndrome or endocrinopathies . of those 32 cases , the mean age was 55.3 years while the male - to - female ratio was 84.3 to 15.7 . the mean bmi of domestic cases was 26.5 , which was less than that of foreign cases . the idiopathic sel group among koreans took up 68.8% , which was significantly different from that of the f reign cases . the secondary sel group of foreign cases took up 62% to 75%1,8,9,13 ) . in the analysis of inflicted area , idiopathic sel cases usually involved the lumbar segments while the secondary sel group involved the thoracic spine . in our review , surgical intervention was carried out in 23 cases ( 78.1% ) and the result of surgery was excellent to good in every case except for one case of mortality which was related to medical complications3,4,5,6,7,11,12,14,15,16,17,18,19,21,22,24,25,27,28 ) . in summary , cases of korean showed higher incidences of idiopathic sel , for which the infliction ( fat lesion ) was manifested predominantly in the lumbar segments , and rarely developed in the thoracic segments , while korean patients had a lower bmi , in comparison with that of western cases . the inquiry of these case studies is the first comparative analysis between korean and western sel cases . koreans had higher incidences of idiopathic sel , predominant involvement in the lumbar segments , very few thoracic involvement and lower bmi , as opposed to westerners . owing to the lack of a large series of korean sel cases , direct comparisons with western reports may not be conclusive and further studies are needed in the days ahead including systemic analysis and multi - center study .
spinal epidural lipomatosis ( sel ) is a rare disorder , regarded in literature as a consequence of administration of exogenous steroids , associated with a variety of systemic diseases , endocrinopathies and the cushing 's syndrome . 
 occasionally , sel may occur in patients not exposed to steroids or suffering from endocrinopathies , namely , idiopathic sel . 
 thus far , case studies of sel among korean have been published rather sporadically . 
 we reviewed the clinical features of sel cases , among koreans with journal review , including this report of three operated cases . according to this study 
 , there were some differences between korean and western cases . 
 koreans had higher incidences of idiopathic sel , predominant involvement in the lumbar segments , very few thoracic involvement and lower mbi , as opposed to westerners .