Abstract

Background: Asymptomatic cervical dumbbell-type tumors can be incidentally diagnosed. Notably, the chronological changes in the size of these tumors have not been satisfactorily described.

Case Description: A 57-year-old man was clinically followed for an asymptomatic cervical dumbbell-type tumor that had the appearance of a schwannoma on magnetic resonance (MR) images obtained over a 7-year period. Notably, the tumor compressed both the spinal cord and the right vertebral artery. At the end of the 7-year period, the patient sustained a cerebral infarction due to atherosclerosis of the right vertebral artery; the angiogram revealed both atherosclerosis and the tumor compressing the right vertebral artery. After the stroke/ischemic event, the tumor progressively shrunk on MR images obtained for the following 4 years, and the spinal cord compression was similarly relieved.

Conclusion: Here, we report on a 57-year-old man with cervical MR images revealing that a cervical dumbbell schwannoma was progressively compressing both the spinal cord and the right vertebral artery. However, following a cerebral infarction, the tumor underwent spontaneous shrinkage over the next 4 years, thus relieving the compression.

Keywords: Cervical dumbbell-type tumor, Ischemic stroke, Natural course, Spontaneous shrinkage, Vertebral artery stenosis

INTRODUCTION

In some cases, conservative treatment may be appropriate for the management of asymptomatic dumbbell-type tumors.[ 4 ] Here, we report an interesting case in which a 57-year-old patient’s cervical dumbbell-type tumor, which was increasing over a 7-year period, spontaneously regressed after a cerebral infarction.

CASE PRESENTATION

For 7 years, a 57-year-old man underwent repeated magnetic resonance (MR) scans that documented progressive spinal cord and right vertebral artery compression attributed to a dumbbell schwannoma with a likely origin in the C4 root. The lesion was isointense on T1-weighted and hyperintense on T2-weighted MR images, and it was heterogeneously enhanced with gadolinium [ Figure 1 ]. Seven years later, the patient sustained a cerebral infarction involving both occipital lobes, which resulted in visual field defects. On angiography, right vertebral compression was attributed both to the tumor and atherosclerosis [ Figure 2 ]. The only treatment we initiated was anticoagulant therapy, to prevent a recurrent infarction. Over the next 4 years, repeated MR imaging studies revealed that the cervical tumor was spontaneously shrinking [ Figure 3 ]. No surgery for tumor removal was indicated.

Figure 1:

Initial radiological characteristics. Sagittal computed tomography images reveal the enlargement of the right C3/4 intervertebral foramen (arrow) and no calcification (a). A cervical dumbbell-type tumor exhibits isointensity on an axial T1-weighted magnetic resonance image (d) and heterogeneous hyperintensity on an axial T2-weighted magnetic resonance image (e). The tumor is heterogeneously enhanced with a gadolinium contrast agent (f). The tumor is located at the C2–4 level (b and c: coronal T1-weighted images with a gadolinium contrast agent). The cervical spinal cord and right vertebral artery (f, arrowhead) are compressed by the tumor.

Figure 2:

Angiographical characteristics. Right vertebral angiography reveals atherosclerotic stenosis of the V4 segment (arrowheads), and the V2 segment of the right vertebral artery is medially shifted (arrow) (a). Blood flow to the right V4 segment from the left vertebral artery is observed through left vertebral angiography (b). The blood flow is interrupted upon right vertebral angiography performed during right rotation of the neck (c).

Figure 3:

Comparison of initial and follow-up magnetic resonance images. Gadolinium-enhanced, T1-weighted magnetic resonance images reveal spontaneous shrinkage of the cervical dumbbell-type tumor (a-d: Initial images, e-h: Follow-up images, 7 years after the initial examination).

DISCUSSION

Concerning spontaneous shrinkage of spinal schwannomas, both a vascular theory (necrosis and bleeding due to thrombi in hyalinized and dilated vessels) and a mechanical theory (laceration of intratumoral arteries due to vertebral motion) of shrinkage have been proposed [ Table 1 ].[ 1 - 4 ] However, in our case, no preceding intratumoral hemorrhage (i.e., reabsorption of a hematoma) was observed. Alternatively, cerebral angiography might have revealed that the blood supply to the right vertebral artery was insufficient owing to both atherosclerosis and tumor compression; however, such angiography was never performed. Further, as surgical treatment was not required in this study, we could not make a definitive pathological diagnosis of schwannoma.

Table 1:

Summary of references.

CONCLUSION

A cervical dumbbell-type tumor (likely a schwannoma) may spontaneously shrink following a cerebral infarction.

Declaration of patient consent

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

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 the 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.

References

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2. Luxon LM, Harrison MJ. Subarachnoid hemorrhage and papilledema due to a cervical neurilemmoma. Case report. J Neurosurg. 1978. 48: 1015-8

3. Mills B, Marks PV, Nixon JM. Spinal subarachnoid haemorrhage from an “ancient” schwannoma of the cervical spine. Br J Neurosurg. 1993. 7: 557-9

4. Suzuki M, Aizawa T, Hashimoto K, Kanno H, Onoda Y, Itoi E. Spontaneous regression of a thoracic dumbbell tumor: A case report. J East Jpn Orthop Traumatol. 2020. 32: 198-201