Case of anterolateral migration of herniated cervical disc fragment mimicking a spinal meningioma.

BACKGROUND: Before the introduction of high-resolution MR, few disc fragments were misdiagnosed as meningiomas. CASE DESCRIPTION: A 63-year-old female presented with a 6-month history of mild to moderate pain in the left arm, weakness 4/5 in the left arm C5-C6 distribution, and a loss of the left biceps reflex response. Although the MR study was read as showing a C5-C6 level probable spinal meningioma, this proved to be a sequestrated disc fragment at surgery.
CONCLUSION: Rarely, cervical disc herniations may be misdiagnosed on MR studies as spinal meningiomas. Copyright:

INTRODUCTION

Spinal meningiomas represent 7.8% of all meningiomas, and 35% are found in the cervical spine.[7] Here, we present a patient with an extramedullary/extradural sequestrated cervical disc herniation which on MR was misdiagnosed as a C5-C6 cervical spinal meningioma.

CASE REPORT

A 63-year-old female presented with mild/moderate pain left arm pain, 4/5 weakness in the left C5-C6 distributions, and a decreased biceps reflex. The original MR was interpreted as a C5-C6 cervical meningioma (i.e. including the classical “dural tail” sign) [Figure 1]. Utilizing a microscopic tubular approach, a left C5 hemilaminectomy with foraminotomy were performed, revealing a left-sided C5-C6 disc herniation that was then removed [Figure 2]. Within 2 postoperative days, by the time of discharge, she had experienced immediate improvement in her symptoms/signs. The histopathology was consistent with an intervertebral disc herniation, and definitively ruled out a meningioma. The postoperative contrasted CT obtained immediately postsurgery, confirmed full lesion resection [Figure 3].

Figure 1:

(a) Sagittal T1 MR; hypo-isointense C5-C6 lesion (b) Sagittal T2 sequence hyperintense lesion intraspinal, extramedullary, extradural lesion. (c) Heterogeneous enhancement with “dural tail” sign. D. axial T2 hyperintense lesion projects toward left neuroforamen, compressing left C5 root. E. Contrast axial section, a poorly defined lesion is seen. Suspicion of spinal meningioma.

Figure 2:

(a) Left C5 lamina identified with minimally invasive tubular approach. (b) Left C5 hemilaminectomy performed. With diamond burr. (c) Black arrow, Spinal root of C5 separated with a hook. White arrow, showed axilla of C5 root compressed by soft, vascularized, gray/whitish lesion. (d) Spinal root C5 released (Gray arrow).

Figure 3:

(a) On the postoperative CT, the C5 the left C5 hemilaminectomy was demonstrated; with contrast removal of the lesion is confirmed. (b) Sagittal cervical contrast CT documenting resection of the C5-C6 lesion/disc herniation.

DISCUSSION

Migration of epidural herniated cervical disc fragments is rare and must be differentiated in some instances from spinal meningiomas.[2] In this case, as typical for others as well, the sequestrated disc fragments appeared hypointense on T1- and hyperintense on T2-weighted images (i.e., present in 80% of cases).[3]

Further, on occasion, contrast-enhanced MR studies of sequestrated disc fragments may demonstrate peripheral/diffuse enhancement that mimics the “dural tail sign” seen with extradural meningiomas classical for meningiomas.[5]

Literature on sequestrated cervical discs

In multiple studies, sequestrated extradural/ extramedullary cervical disc fragments may closely resemble spinal meningiomas.[4] In 2011, Srinivasan et al. suggested that sequestered epidural discs are rare and found only ten cases in the literature.[6] When Babashahi, et al. (2015) evaluated 52 cases of sequestered disc fragments imitating other pathologies; only six were located in the cervical spine, with 13 MR images resembling those found in the case we presented (i.e. especially on the T1 sequence) [Table 1].[1]

Table 1:

Cases reported so far of cervical hernia mimicking other pathologies.

CONCLUSION

On occasion, sequestrated epidural cervical disc herniations may migrate and imitate intra-spinal meningiomas or other tumors on MR studies performed with/without contrast. Here, surgical intervention readily differentiated between a cervical disc herniation versus meningioma/other neoplasm.