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Extradural en-plaque spinal lipomatous meningioma: A case report and literature review

Background: Extradural spinal meningiomas are rare, and few appear as lipomatous meningiomas in an “en-plaque” form. The transitional fibroblastic subtype, with lipid accumulation within the tumoral cells, is typically more aggressive and surgically challenging to resect. Case Description: A 42-year-old male presented with neck pain and progressive paresthesias in both upper extremities. Based on the radiological findings, the tentative preoperative diagnosis was lymphoma. However, the biopsy confirmed a meningioma. The patient underwent a combined extradural anterior and posterior approach, resulting in full tumor resection. Histopathologically, the final report documented a lipomatous meningioma. Conclusion: Extradural spinal lipomatous meningiomas (i.e., “en-plaque”) are rare and typically result in rapid clinical deterioration. The radiological diagnosis may be difficult, while ultrasonography helps to define their extradural location facilitating planning for gross total anterior/posterior excision where indicated.


INTRODUCTION
Spinal meningiomas account for approximately 25% of primary spinal cord tumors. [5] ey are usually intradural extramedullary in location and have a predilection for the thoracic spine. [1] Morphologically, they are typically round but may occasionally appear "en-plaque;" the latter histopathological diagnosis is occasionally meningothelial/psammomatous with lipomatous variants (e.g., additional presence of adipocytes). Gross total resection is often challenging and may warrant a combined anterior/posterior approach. Here, we describe a 42-year-old male who successfully underwent gross-total resection of a cervical lipomatous extradural "en-plaque" meningioma.

CASE REPORT Clinical and radiographic presentation
A 42-year-old male presented with neck pain, progressive paresthesias, tightness in both upper extremities, and 6 months of numbness involving the fourth and fifth digits of the left hand. His only neurological deficit was decreased pin appreciation in the left 4 th and 5 th digits. e magnetic resonance image (MRI) showed a circumferential tumor extending from C2 to C7 levels, resulting in maximal cord compression between C3 and C5. e lesion was isointense on both T1-and T2-weighted images and intensely homogeneously enhanced with gadolinium [ Figure 1].

Biopsy and surgery
After an open biopsy revealed a meningioma, the patient initially underwent a C3-C7 laminoplasty, with theremoval of posterior tumor, and decompression of the dural sac. At surgery, the extradural tumor was grayish, white, non-suckable, and fibrous; it was carefully peeled off the dura [ Figure 2]. e intraoperative ultrasound confirmed adequate posterior decompression of the spinal cord without the identification of any additional intradural mass [ Figure 3]. Electrophysiological monitoring showed no significant changes during meticulous tumor removal.
When the postoperative MRI documented residual anterior tumor, the patient underwent a C4 and C5 anterior corpectomy/fusion to achieve gross total tumor resection.

Histopathology
Histopathological analysis revealed meningothelial uniform cells accompanied by mature adipocyte-like cells with peripherally displaced nuclei (e.g., ovoid nuclei with stippled chromatin and eosinophilic cytoplasm with fat vacuoles in their cytoplasm). ere was no necrosis, mitotic activity, or hemorrhage. ese findings confirmed the diagnosis of a transitional lipomatous meningioma [ Figure 4].
For 3 postoperative years, the patient has remained asymptomatic and follow-up MR studies showed no residual/recurrent disease [ Figure 5].

Recommended surgical management of ESM
Gross total excision is the procedure of choice for managing ESM.
In addition, there are various adjuvant therapies that may be utilized (e.g., so as to treat atypical or malignant meningiomas). [7] Since these are thick, fibrous, and occasionally calcified lesions that often encircle/scathe dura, complete removal frequently requires a combined anterior/posterior approach.

Recurrence rate of ESM
Over a 5-year period, lipomatous ESMs typically show rapid clinical progression and are 4 times more likely to recur versus typical intradural meningiomas; recurrences are much more frequent following initial subtotal resection. [9,10] In this case, following a gross total resection, the patient has remained disease free over 3 postoperative years.

CONCLUSIONS
En-plaque lipomatous ESMs are rare extradural lesions that often demonstrate rapid clinical and radiographic progression. As they are thick, fibrous, tenacious, often calcified, and may encircle the dura, gross total surgical excision may warrant combined anterior/ posterior approaches.

Declaration of patient consent
e authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. e patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship
Nil.

Conflicts of interest
ere are no conflicts of interest.