Abstract

Background: Pseudotumors are rare lesions that may cause compression of adjacent neural structures. Treatment options range from conservative management to surgical intervention.

Case Description: A 59-year-old female presented with a 3-month history of headaches, difficulty speaking, swallowing, gait disturbance, and progressive left-sided weakness. Her examination confirmed left-sided tetraparesis. The cervical magnetic resonance showed a right-sided mass compressing the bulbomedullary junction. Through a modified right-sided far lateral craniotomy, an intradural “pseudotumor” was removed. Postoperatively, the patient’s symptoms gradually improved. Histopathological analysis revealed an acellular fibrocartilaginous mass consistent with the diagnosis of pseudotumor.

Conclusion: Pseudotumors at the craniocervical junction may cause progressive tetraparesis readily resolved following gross total surgical excision.

Keywords: Bulbomedullary compression, Craniocervical pseudotumor, Far lateral craniotomy, Myelopathy

INTRODUCTION

Neoplastic lesions at the cervicomedullary junction may include aneurysmal bone cysts, osteoblastomas, chondromas, meningiomas, malignant chondrosarcomas, metastatic tumors, and rarely, degenerative pseudotumors. Pseudotumors consist of amorphous degenerative fibrocartilaginous material that is typically caused by a reactive soft-tissue response to chronic subluxation.[ 4 ] Surgery may include posterior or anterior procedures. Here, a 59-year-old female with a progressive tetraparesis underwent gross total resection of a cervicomedullary pseudotumor resulting in symptomatic improvement.

CASE REPORT

Clinical presentation

A 59-year-old female presented with 3 months of headaches, difficulty speaking/swallowing, gait disturbance, and progressive left-sided weakness. On examination, she exhibited dysarthria/dysphagia, was tetraparetic (left worse than right), had decreased bilateral lower extremity light touch sensation, and hyperreflexia in all extremities. The cervical magnetic resonance (MR) at C1/C2 showed a dorsal right inferior clival lesion at the bulbomedullary junction that was intradural extra-axial in location (i.e., 19 × 10 × 8 mm) [ Figures 1a and b ]. The lesion was hyperintense on the T2 W study but did not enhance. Additional findings included mild anterior atlanto-occipital dislocation of C1 relative to C0 and an atlas-dens interval of 1.5 mm. The cervical computed tomography (CT) showed no bony abnormalities, while dynamic X-rays confirmed no instability. Of interest, the cranial MR was normal. Preoperative somatosensory evoked potentials were intact, but upper extremity electromyography was consistent with multilevel chronic radiculopathy.

Figure 1:

(a) Preoperative sagittal T2-weighted MRI sequence revealing a hyperintense lesion (arrow) located at the craniocervical junction that extends from the tip of the odontoid process to the base of C2. (b) Preoperative axial T2-weighted MRI sequence showing the hyperintense lesion (arrow) with right-sided compression of the bulbomedullary transition.

Surgery

In the left lateral decubitus position, a 3-pin head holder was applied. The head was slightly flexed and rotated to the left. Through a right suboccipital hockey stick incision, a modified far lateral right craniotomy was performed that included the removal of the right C1 posterior arch. Upon opening the dura, the right vertebral artery, right posterior inferior cerebellar artery, medullary origin of the right XI nerve, and C1 and C2 nerve roots were clearly visualized [ Figure 2a ]. Once the lesion’s capsule was opened, mucinous yellowish tissue was readily aspirated [ Figure 2b ]. It was removed, and due to adhesions, so was the dorsal origin of the right C1 nerve root. The dura was closed with a watertight duraplasty. Immediately postoperatively, the patient’s dysphagia and tetraparesis rapidly improved, and she was discharged 5 days later. The postoperative CT scan confirmed no residual lesion. Three months later, the MR further documented total resection of the pseudotumor [ Figures 3a and b ]. One year later, all symptoms had improved and she showed no signs of instability.

Figure 2:

(a) Intraoperative view of the lesion. A - Right posterior inferior cerebellar artery; B - Right vertebral artery; C - Medullary origin of the right XI nerve. (b) Intraoperative view of the lesion after opening of the capsule.

Figure 3:

(a) Three-month postoperative sagittal T2-weighted MRI sequence showing total resection of the lesion with no complications. (b) Three-month postoperative axial T2-weighted MRI sequence with complete resection of the lesion lateral to the bulb.

Histopathology

The histopathology was consistent with a paucicellular, noninflammatory pseudotumor. It contained small fragments of fibrocartilaginous tissue, with recognizable degenerative elements (i.e., fibrin deposits and cholesterol crystals/cavities). No epithelium, neoplastic, or inflammatory cells were present [ Figure 4 ].

Figure 4:

Hematoxylin and eosin stain (at ×100 magnification): Small fragments of fibrocartilaginous tissue, with recognizable degenerative elements, such as fibrin deposits and cholesterol crystal cavities. Neither epithelium nor neoplastic or inflammatory cells were observed.

DISCUSSION

Cervical pseudotumors contain amorphous degenerative fibrocartilaginous material.[ 3 ] These lesions are thought to arise due to chronic instability in the atlantoaxial joints (i.e., similar to synovial cysts). The main differential diagnosis for pseudotumors is synovial cysts. They are more common in the lumbar spine, with only 2.6–4% occurring in the cervical region typically (i.e., one-third) at the C7-T1 level but can also involve the atlantoaxial joints.[ 1 ]

Surgical options

Surgical options typically include total or subtotal removal with/without fusion. In Theodotou et al. 70 cases of craniocervical cysts, in which patients underwent surgical decompression, the outcomes were comparable for either complete vs. subtotal resections. Patients undergoing anterior resections through a transoral approach experienced greater perioperative morbidity and typically required posterior fusions (i.e., instability due to resection of the anterior C1 arch).[ 8 ] Anterior endoscopic approaches had fewer complications but were only suitable for lesions above the hard palate.[ 5 ] Alternatively, for posterior approaches, suboccipital craniotomy allowed for resection of paramedian pseudocysts but typically required dural opening, even for extradural lesions.[ 7 ] Lateral and far lateral posterior approaches provided wide exposure of the craniocervical junction while reducing dural traction, thus lowering the risk of cranial nerve dysfunction.[ 6 ] Posterior approaches also allow for instrumentation if indicated in the same sitting.[ 2 ] Table 1 summarizes surgical options for patients with craniocervical lesions. Here, we performed a transdural gross total resection of the pseudotumor without fusion. One year postoperatively, the lesion did not recur, and the patient was not unstable.

Table 1:

Summary table of data for patients with craniocervical lesions.

CONCLUSION

A 59-year-old female underwent successful decompression alone without fusion of a symptomatic craniocervical pseudotumor. Postoperatively, she clinically improved and demonstrated no cervical instability.

Ethical approval:

Institutional Review Board approval is not required.

Declaration of patient consent:

The authors certify that they have obtained all appropriate patient consent.

Financial support and sponsorship:

Nil.

Conflicts of interest:

There are no conflicts of interest.

Use of artificial intelligence (AI)-assisted technology for manuscript preparation:

The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript and no images were manipulated using AI.

Disclaimer

The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Journal or its management. The information contained in this article should not be considered to be medical advice; patients should consult their own physicians for advice as to their specific medical needs.

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