Radiculopathy in the setting of lumbar nerve root compression due to an extradural intraforaminal lipoma: a report of 3 cases

Abstract

<jats:p>A true adult spinal lipoma is an exceedingly rare cause of lumbar compression neuropathy. Only 5 cases of true extradural intraforaminal lipomas have been documented in the medical literature. The diagnostic criteria and treatment guidelines for this specific lipoma have yet to be established. This report features 3 histologically confirmed cases of extradural intraforaminal spinal lipomas that recently presented to the authors’ practice. In addition, the literature was surveyed to include the 5 previously reported cases of true adult extradural intraforaminal spinal lipomas. The consistency in presentation, response to surgical intervention, and postoperative recovery in these 8 cases supports surgical intervention at the time of diagnosis. The authors’ findings support elevated clinical suspicion, efficient diagnosis based on MRI, and early surgical intervention for this rare pathological entity. All cases presented in this report were symptomatic and occurred in the absence of other significant pathologies such as general spinal epidural lipomatosis, intradural lesions, tethering, or severe degenerative stenosis or herniated discs. The clinical, neuroradiological, and histological findings characteristic of a true adult extradural intraforaminal lipoma are emphasized to differentiate this lesion from the more common etiologies for lumbar compression neuropathy. Heightened awareness and clinical suspicion for the focal, foraminal spinal lipoma as a cause of radiculopathy symptoms will enable more efficient diagnosis and treatment.</jats:p>

A new pattern of lipomatosis of nerve: case report

“…The circumferential proliferation of fat around spinal nerves represents a new finding; this produces an MRI pattern different from classic LN in the distal limbs 2,8 and different from extradural compression of spinal nerves by isolated intraforaminal lipomas. 4,5,13 Although the typical pattern of LN involves interfascicular fat proliferation, producing a spaghetti-like appearance on MRI, 2,8 there are instances when fat proliferates around the nerve 12 similar to the cases discussed in this report. We have previously highlighted the similarity of this pattern to lipomatosis of the digital nerves in the fingers.…”

An intraspinal extradural lipoma with spinal epidural lipomatosis: A case report and a review of literature

“…There are a few cases of intraspinal extradural lipoma without spinal dysraphism. Here, we reviewed 10 studies in the literature and summarized the diagnosis and surgical management of this 76-year-old male[ 3 4 5 6 8 9 ] [ Table 1 ].…”

“…reported three patients with radiculopathy attributed to extradural/intraforaminal lipomas; these lesions were all small (1.1 × 0.8 × 0.2 cm, 1.1 × 1.1 × 0.3 cm, and 2.5 × 1.6 × 0.3 cm). [ 4 ] The “empty foramen sign” on MRI reflected displacement of the nerve root cranially or caudally due to intraforaminal lipoma. [ 4 ]…”

“…[ 4 ] The “empty foramen sign” on MRI reflected displacement of the nerve root cranially or caudally due to intraforaminal lipoma. [ 4 ]…”

“…It accounts for only 0.4%–0.8% of all intraspinal tumors. [ 2 4 9 ] Differentiation of an intraspinal extradural lipoma from spinal epidural lipomatosis (SEL – overgrown normal adipose tissue in the epidural space[ 1 ]) and angiolipomas (e.g. 0.14% of all spinal tumor containing vascular tissue[ 7 ]) is imperative.…”