Spontaneous resorption in recurrent intradural lumbar disc herniation

Transcription

1 J Neurosurg Spine 6: , 2007 Spontaneous resorption in recurrent intradural lumbar disc herniation Case report TSUBASA SAKAI, M.D., 1 TAKASHI TSUJI, M.D., 1,2 TAKASHI ASAZUMA, M.D., 1 YOSHIYUKI YATO, M.D., 1 OSAMU MATSUBARA, M.D., 3 AND KOICHI NEMOTO, M.D. 1 Departments of 1 Orthopaedic Surgery and 3 Pathology, National Defense Medical College, Tokorozawa, Saitama; and 2 Department of Orthopaedic Surgery, Keio University, Tokyo, Japan The authors report a case of spontaneous resorption of intradural disc material in a patient with recurrent intradural lumbar disc herniation and review magnetic resonance (MR) imaging and histopathological findings. Intradural lumbar disc herniation is rare, and most patients with this condition require surgical intervention due to severe leg pain and vesicorectal disturbance. In the present case, however, the recurrent intradural herniated mass had completely disappeared by 9 months after onset. Histological examination of intradural herniated disc tissue demonstrated infiltrated macrophages and angiogenesis within the herniated tissue, and Gd-enhanced MR images showed rim enhancement not only at the initial presentation, but also at recurrence. The authors conclude that when rim enhancement is present on Gd-enhanced MR images, there is a possibility of spontaneous resorption even though the herniated mass may be located within the intradural space. Moreover, when radiculopathy is controllable and cauda equina syndrome is absent, conservative therapy can be selected. KEY WORDS intervertebral disc herniation intradural lesion spontaneous regression magnetic resonance imaging rim enhancement MANY reports have described the spontaneous regression of intervertebral disc herniation, and conservative therapy is not a rare option. 5,6,10,16 On the other hand, many patients with intradural disc herniation require surgical intervention due to severe leg pain and vesicorectal disturbances. 8,13 Here, we report a case of recurrent intradural lumbar disc herniation in which there was spontaneous resorption with conservative therapy. Case Report History and Presentation. This 72-year-old woman with bilateral thigh pain and gait disturbance was referred to our institute after presenting to another institution, where her condition had been diagnosed as being due to a spinal tumor. On admission, she had severe bilateral leg pain. Abbreviation used in this paper: MR = magnetic resonance. Examination. Sensory examination did not demonstrate decreased sensation of touch and pain. Motor examination demonstrated bilateral muscle weakness of the iliopsoas, tibialis anterior, and extensor hallucis longus (results of manual muscle testing, Grade 3 4). The patient did not complain of vesicorectal disturbance. Magnetic resonance imaging demonstrated an intradural mass at the L2 3 level. The mass was isointense on T 1 - and T 2 -weighted images and showed rim enhancement on Gdenhanced images (Fig. 1). A myelogram demonstrated a capping defect at the L2 3 level. On the basis of these findings, we diagnosed an intradural disc herniation or a tumor at the cauda equina. Because the patient had motor paresis and intolerable leg pain, she underwent surgical treatment. Operation and Postoperative Course. The mass was found to have completely penetrated the ventral dura mater, but the ventral dura adhered firmly to the tissue of the L2 3 disc space (Fig. 2). Although the large, firm mass was wrapped with abundant blood vessels, it did not adhere to 574 J. Neurosurg: Spine / Volume 6 / June, 2007

2 Spontaneous resorption in recurrent intradural disc herniation FIG. 1. Preoperative sagittal (left) and axial (right) T 1 -weighted Gd-enhanced MR images showing an intradural mass with rim enhancement at the L2 3 level. the surrounding tissue. Examination of frozen sections revealed cartilage tissue and no evidence of malignancy, and we therefore resected the mass piecemeal. After resection of the mass, the dorsal dura mater was repaired and a 90 rotational laminoplasty 1 of L-2 was performed. Subsequent histopathological examination of H & E stained sections revealed intervertebral disc tissue and infiltrated granulation tissue. The tissue contained many macrophages and capillary vessels (Fig. 3). The patient had a prompt recovery of neurological function and complete resolution of the leg pain. Postoperative MR images showed no residual mass (Fig. 4). Recurrence and Resolution. At 9 months after the surgery, however, the patient again complained of bilateral thigh pain, and Gd-enhanced MR images obtained at this time showed an intradural mass with rim enhancement at the L2 3 level (Fig. 5). A recurrence of the intradural disc herniation was diagnosed. We expected a spontaneous resorp- FIG. 2. Intraoperative photograph showing the large intradural herniated mass (arrow), which was wrapped with abundant blood vessels and is not adhering to the surrounding tissue. FIG. 3. Photomicrograph of a section of the intradural herniated mass showing abundant infiltrated macrophages (dark arrows) and capillaries (white arrows). H & E. Bar = 200 m. J. Neurosurg: Spine / Volume 6 / June,

3 T. Sakai et al. FIG. 4. Sagittal (left) and axial (right) T 1 -weighted MR images obtained 3 months postoperatively showing absence of intradural mass. tion of the mass because of the MR imaging finding of rim enhancement and the findings at the first operation. Because the patient only suffered from thigh pain without cauda equina syndrome and motor paresis, we opted for conservative therapy. Follow Up. At the follow-up examination 3 months after the recurrence, the patient was found to be slowly recovering, and MR images showed a contracting mass. Nine months after the recurrence, the mass had completely disappeared (Fig. 6). FIG. 5. Sagittal (left) and axial (right) T 1 -weighted Gd-enhanced MR images obtained 9 months postoperatively showing recurrence of the mass with rim enhancement at the L2 3 level. 576 J. Neurosurg: Spine / Volume 6 / June, 2007

4 Spontaneous resorption in recurrent intradural disc herniation FIG. 6. Sagittal (left) and axial (right) T 1 -weighted Gd-enhanced MR images obtained 9 months after the recurrence showing complete resolution of the mass. Discussion The first reported case of an intradural disc herniation was described by Dandy in The incidence of intradural disc herniation is low, with intradural herniations constituting only 0.04 to 0.33% of lumbar disc herniations. 4,8,12 Intradural disc herniation is usually seen at the L4 5 level, but more than one third of intradural disc herniations involve the L1 2 through L3 4 levels. 3,8,9,12,13 Symptoms often include severe leg pain, and cauda equine syndrome is found in two thirds of patients. 13 Kataoka 8 and Schisano 13 and their colleagues concluded that prompt surgical intervention is important because favorable results are obtained if surgery is performed before the neurological deficit becomes too pronounced. All of the previous reports involve surgical cases, and the present case is the first one involving spontaneous resorption of disc material in recurrent intradural disc herniation to be reported in the English-language literature. The spontaneous resorption of disc tissue in a case of extradural disc herniation was first reported by Guinto et al. 5 in 1984, and many authors have since reported this phenomenon. The mechanism of spontaneous resorption has been reported to be associated with infiltration of new blood vessels, macrophage phagocytosis, the production of matrix metalloproteinases, and increased cytokine levels. 6,7 In the present study, we found angiogenesis and infiltration of macrophages within the intradural herniated disc, which suggested the possibility of spontaneous resorption of the intradural herniated mass. No detailed MR imaging findings of intradural disc herniation have been reported. We reviewed past reports in which Gd-enhanced MR images were obtained in patients with intradural disc herniation and found that rim enhancement was present on Gd-enhanced MR images in 10 of 12 cases (Table 1). According to the current studies of extradural lumbar disc herniation, a herniated mass that shows rim enhancement on Gd-enhanced MR images disappears or markedly decreases in 75 to 100% of cases. 10,16 Rim enhancement on MR images has been reported to be related to the accumulation of contrast material within the vascularized granulation tissue surrounding the avascular sequestrated disc. 10,16 Together, these findings suggest that spontaneous resorption is possible in intradural disc herniations that show rim enhancement. TABLE 1 Findings of rim enhancement on Gd-enhanced MR images in cases of intradural disc herniation Authors & Year Rim Enhancement* Wasserstrom et al., /1 Lidov et al., /1 Whittaker & Bernhardt, /1 Prestar & Schattke, /1 Hida et al., /1 Koç et al., /1 Aydin et al., /1 D Andrea et al., /4 present case 1/1 total 10/12 *Number of cases with positive findings per number of cases reported. J. Neurosurg: Spine / Volume 6 / June,

5 T. Sakai et al. Therefore, when rim enhancement is evident on Gd-enhanced MR images, there is a possibility of spontaneous resorption even though the herniated mass may be within the intradural space. Moreover, on occasions when radiculopathy is controllable and cauda equina syndrome is absent, conservative therapy may represent the best option. References 1. Asazuma T, Yamagishi M, Sato M, Ichimura S, Fujikawa K: Vertebral arch reconstruction based on 90 degree rotational laminoplasty after removal of spinal cord and cauda equina tumors. Acta Neurochir (Wien) 145: , Aydin MV, Ozel S, Sen O, Erdogan B, Yildirim T: Intradural disc mimicking: a spinal tumor lesion. Spinal Cord 42:52 54, D Andrea G, Trillò G, Roperto R, Celli P, Orlando ER, Ferrante L: Intradural lumbar disc herniations: the role of MRI in preoperative diagnosis and review of the literature. Neurosurg Rev 27: 75 82, Dandy WE: Serious complications of ruptured intervertebral discs. JAMA 119: , Guinto FC Jr, Hashim H, Stumer M: CT demonstration of disk regression after conservative therapy. AJNR Am J Neuroradiol 5: , Haro H, Shinomiya K, Komori H, Okawa A, Saito I, Miyasaka N, et al: Upregulated expression of chemokines in herniated nucleus pulposus resorption. Spine 21: , Hida K, Iwasaki Y, Abe H, Shimazaki M, Matsuzaki T: Magnetic resonance imaging of intradural lumbar disc herniation. J Clin Neurosci 6: , Kataoka O, Nishibayashi Y, Sho T: Intradural lumbar disc herniation: report of three cases with a review of the literature. Spine 14: , Koç RK, Akdemir H, Öktem IS, Menkü A: Intradural lumbar disc herniation. Report of two cases. Neurosurg Rev 24:44 47, Komori H, Okawa A, Haro H, Muneta T, Yamamoto H, Shinomiya K: Contrast-enhanced magnetic resonance imaging in conservative management of lumbar disc herniation. Spine 23: 67 73, Lidov M, Stollman A, Casden A, Som P, Bederson J: MRI of lumbar intradural disc herniation. Clin Imaging 18: , Prestar FJ, Schattke HH: Intradural lumbar disc herniations: report of three cases. Minim Invasive Neurosurg 38: , Schisano G, Franco A, Nina P: Intraradicular and intradural lumbar disc herniation: experiences with nine cases. Surg Neurol 44: , Wasserstrom R, Mamourian AC, Black JF, Lehman RA: Intradural lumbar disk fragment with ring enhancement on MR. AJNR Am J Neuroradiol 14: , Whittaker CK, Bernhardt M: Magnetic resonance imaging shows gadolinium enhancement of intradural herniated disc. Spine 19: , Yamashita K, Hiroshima K, Kurata A: Gadolinium-DTPAenhanced magnetic resonance imaging of a sequestered lumbar intervertebral disc and its correlation with pathologic findings. Spine 19: , 1994 Manuscript submitted August 18, Accepted March 5, Address reprint requests to: Tsubasa Sakai, M.D., Department of Orthopaedic Surgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, , Japan. ts2611@ hotmail.com. 578 J. Neurosurg: Spine / Volume 6 / June, 2007