A 50-year-old female patient presented to our radiology department complaining of lumbar and right lower extremity pain and weakness. Magnetic resonance imaging (MRI) of the lumbo-sacral spine demonstrated severe circumferential compression of the dural sac (from L5 to S1) caused by significant epidural fat hypertrophy (Fig. 1a–c). The compressed thecal sac adopted a “Y” configuration (Fig. 2), a finding characteristic of a grade III Borré et al. spinal epidural lipomatosis (SEL).

Fig. 1
figure 1

Midsagittal T1 (a), T2 (b), and STIR (c) weighted images show a large amount of circumferential epidural fat (black and white arrows) surrounding the dural sac at level L5-S1. No other substantial lumbar spine abnormality is present

Fig. 2
figure 2

Axial T2-weighted images at L5-S1 interspace (a) and S1 superior end plate (b) demonstrate the pathognomonic “Y” shape of the dural sac

SEL is a rare condition characterized by nonencapsulated adipose tissue accumulation in the thoracic or lumbar spinal canal’s epidural space which can cause spinal cord or nerve root compression [1, 2]. It can be due to chronic steroid therapy (55% of cases), obesity (25%), Cushing’s syndrome (3%), or idiopathic (17%) [3]. According to recent studies, SEL should be contemplated as a metabolic syndrome manifestation, alongside increased BMI, abdominal circumference, and visceral and liver fat deposits [4]. To diagnose and grade this condition, MRI is the gold standard imaging modality. Mild (grade I) SEL is asymptomatic, moderate (grade II) SEL is symptomatic in 14.5% of cases, whereas all severe (grade III) SEL cases are symptomatic [1]. Weight loss and/or steroids suspension are efficient therapeutic strategies. When conservative approaches fail, surgical management involving decompressive laminectomy and epidural adipose tissue excision is indicated [5].