Congenital lumbosacral lipomas

Abstract

Congenital lumbosacral lipomas can be responsible for progressive defects. The general feeling is that tethering of roots, filum, or cord probably explains this evolution, and that untethering of these structures could prevent late deterioration. Like the vast majority of neurosurgeons, we too have routinely and systematically operated on lumbosacral lipomas, even in the absence of neurological deficits. This policy stemmed from our belief that spontaneous neurological deterioration was frequent, recovery from preoperative deficits rare, and surgery both efficient and benign in nature. After 22 years of experience, we felt that it was necessary to review our series of 291 lipomas (38 lipomas of the filum and 253 of the conus) operated on from 1972 to 1994. To reassess the value of prophylactic surgery, we attempted an accurate evaluation of (1) the risk of pathology, (2) the risks involved in surgery, (3) the postoperative outcome with respect to preoperative deficits, and (4) the postoperative outcome in asymptomatic patients at 1 year and at maximum follow-up. Special attention was paid to 93 patients whose postoperative follow-up was more than 5 years (average 8.7, median 8, range 5-23 years). Of these 93 patients, 39 were asymptomatic preoperatively (7 with lipoma of the filum and 32 with lipoma of the conus). Lipomas of the filum and of the conus are entirely different lesions and were studied separately. In 6 cases prenatal diagnosis had been possible. The mean age at surgery was 6.4 years. Low back skin stigmata were present in 89.4% of cases. Preoperative neurological deficits existed in 57% of the patients and were congenital in 22%. Clinical signs and symptoms recorded were pain in 13.3% of the patients and/or neurological deficits affecting sphincter (52%), motor (27.6%) and sensory (22.4%) functions. Deficits were progressive in 22.4% of cases, slowly progressive in 58.8% of these and rapidly progressive in the remaining 41.2%. In 36 patients (13.2%) the lipomas were seen to grow either subcutaneously or intraspinally. Among these patients, 21 were infants, 2 were obese adolescents, and 10 were pregnant women. The metabolism of the fat within the lipomas was studied in 11 patients and found to be similar to that at other sites. Lipomas were associated with various other malformations, either intra- or extraspinal. These associated anomalies were rare in the case of lipomatous filum (5.2%) but frequent with lipomas of the conus, except for intracranial malformations (3.6%). Therapeutic objectives were spinal cord untethering and decompression, sparing of functional neural tissue and prevention of retethering. Procedures used to achieve these goals were subtotal removal of the lipoma, intraoperative monitoring, duroplasty, and sometimes closure of the placode. Histologically, lipomas consisted of normal mature fat. However, 77% of them also included a wide variety of other tissues, originating from ectoderm, mesoderm, or entoderm. This indicates that lipomas are either simple or complex teratomas. The r...

Lateral tethering intraspinal lipoma with scoliosis

“…Lipomas of conus medullaris are further classified according to Chapman [6] into dorsal, caudal, and transitional lipomas. Intraspinal lipomas are most commonly found in the lumbosacral area (90%) [1,17,23,26]. Excluding the lumbosacral spine, the reported distribution of lipoma was thoracic in 32% of cases, cervicothoracic in 24%, and cervical in 13% [18].…”

Cutaneous Lesions Indicating Occult Spinal Dysraphisms: A Review

“…They may occasionally present as causing spontaneous neurological deterioration secondary to tethering of the cord, filum, or nerve roots (Pierre-Kahn et al, 1997). Lipomas may be localized within the dermis or spinal canal, and can extend from the dermis to the intraspinal space via a concurrent vertebral defect (Drolet, 2000).…”

“…Those associated with the filum have very limited morbidity and may benefit in both the short-term and long-term from surgical intervention. Lipomas associated with the conus display a much higher degree of structural complexity, are correlated with more severe deficits and defects, and may be associated with significant surgical risks (Pierre-Kahn et al, 1997). Given the relatively significant influence these lesions can have on the structural integrity of the spinal cord, investigation of suspicious lesions with imaging is often warranted (Brunelle et al, 1996).…”

Efficacy of electromyography and nerve conduction velocity monitoring in surgical management of terminal lipoma in children

“…The prognosis Terminal (caudal in Chapman 3) lipomas had better than that of other types and locations of spinal lipomas, their surgical management established with no debate of its benefit (1,4,5,15,21). The principle of its management includes total/gross total excision of the lipoma; with separation of neural placode from the dura and reformation of neural tube.…”

“…(15,17,18) As known the dorsal root ganglions generated from neural crest cells at the outer surface of the neural fold then its roots grow ventrolateraly but never traverse, the lipomatous stalk. (4,8,9) …”