spinal epidural lipomatosis ( sel ) is caused by excessive deposition of adipose tissue in the spinal canal , causing spinal cord or cauda equina compression8 ) . the majority of cases have been reported in morbidly obese patients receiving steroid therapy , or suffering from endocrinopathies , such as cushing 's syndrome or hypothyroidism in the thoracic spine231112 ) . here , we describe the case of a young patient discovered to have an epidural lipomatosis after the development of cauda equina syndrome and include a review of the literature . the patient was a healthy 19-year - old man who had experienced back pain for 2 months prior to presentation , but had received no specific treatment . his visit to our emergency room was prompted by the development of motor weakness of the lower extremities and voiding difficulty on the day of the visit . a physical examination revealed a body weight of 60 kg and a height of 175 cm , his body mass index was 19.6 kg / m , which was within the normal range , and laboratory test findings , which included full blood count , electrolytes , creatinine , liver function test , vitamin b12 and folate , urine analysis and culture , thyroid function test , adrenocorticotropic hormone , and cortisol , were all unremarkable . however , a neurological examination revealed a reduction in patellar and achilles tendon reflex in both legs , motor weakness ( grade i / grade i ) , and sensory loss in l4 , l5 , and s1 with a radicular distribution . plain radiographs of the lumbar spine showed no abnormalities . magnetic resonance imaging ( mri ) of the lumbar region showed a posterior compressing mass lesion of increased signal intensity on t1 and t2 weighted images in the epidural space , suggesting epidural lipomatosis at the l3-l4 , l4-l5 and l5-s1 levels ( fig . voiding difficulty , urgent decompressive laminectomies were performed at l3 , l4 , and l5 with fat debulking ( fig . at one year after surgery , he was able to walk without mechanical assistance ( grade v / grade v ) and had returned to fulltime work at a university . sel describes the excessive deposition of histologically normal adipose tissue in the spinal canal , causing compression of the spinal cord or cauda equina . this deposition typically occurs posterior to the cord in the thoracic spine in overweight patients7 ) . it has been well established that the main etiological factors of sel are related to endocrine dysfunctions , such as those associated with cushing 's disease , hypothyroidism , obesity , iatrogenic steroid treatment of immune disorders , copd , and transplantation45 ) . however , it can be present even in the absence of endocrinopathies and in nonobese patients . the term ' idiopathic sel ' is applied to describe cases without definitive predisposing factors , and the occurrence of idiopathic sel in non - obese young patient is exceptional . haddad et al.5 ) first hypothesized that idiopathic sel is a byproduct of obesity , involving gradual overgrowth of epidural fat resulting in spinal cord and nerve roots compression . idiopathic sel causing neurological deficits occurs more frequently in the thoracic than in the lumbar spine . patients may present with progressive and long - standing complaints of pain , weakness , numbness , incontinence , ataxia , abnormal reflexes , and rarely paralysis . epidural lipomatosis commonly presents with localized chronic pain , which has often lasted months to several years , followed by progressive or sudden neurologic deficits . lower - extremity weakness and sensory change are the most common finding during physical examination , though decreased pinprick sensation and altered reflexes are frequently encountered . obviously , symptoms are somewhat dependent on the level of canal compromise ( spinal cord , conus medullaris , or cauda equina)9 ) . plain radiographs of the lumbar spine are usually normal , but mri is the imaging tool of choice . canal compression with obliteration of cerebrospinal fluid spaces can be appreciated on axial and sagittal mr images , and high - signal intensity on t1-weighted images and intermediate signal intensity on t2-weighted images are characteristics of adipose tissue . moreover , short t1 inversion recovery ( stir ) sequence may be useful for confirmation of diagnosis as lipid is hypointense in this sequence . circumferential compression of the thecal sac is referred to as " y - sign " , a trifid appearance of thecal sac , characteristics in axial imaging6 ) . borre et al.1 ) developed four categories of mri grading of lumbosacral epidural lipomatosis attending to the spatial relation between dural sac and epidural fat . but , no reports have answered the question of direct relation between grading system of lipomatosis and symptom development . just weaning of steroids and weight loss or treatment of endocrinopathy can achieve good results . recovery can be either immediate or occur over several months , although reports indicate that the majority of patients experience improvements in neurological symptoms immediately after surgical intervention . furthermore , patients with pathological conditions in the lumbar ( cauda equina ) region tend to make better recoveries following surgical decompression than patients with pathological conditions in the thoracic region10 ) . we report a rare case of idiopathic sel causing cauda equina syndrome in a non - obese young patient . although rare , idiopathic sel should be considered as a cause of cauda equina syndrome .
spinal epidural lipomatosis ( sel ) is a rare condition that presents as a back pain with progressive neurologic symptoms . 
 most affected patients are obese and receiving steroid therapy , or have an endocrinopathies . 
 we report a rare case of cauda equina syndrome caused by sel in a non - obese healthy young man without any evident traumatic episode . a healthy 19-year - old man , who had experienced lower back pain for two months , visited our emergency room because of the sudden development of motor weakness and voiding difficulty . 
 lumbar magnetic resonance image revealed extradural fat compressing the cauda equina . 
 urgent decompression via posterior laminectomy and excision of excess epidural fat resulted in an immediate symptom improvement .