Archives of Medicine and Health Sciences

LETTER TO THE EDITOR
Year
: 2020  |  Volume : 8  |  Issue : 2  |  Page : 316--317

The sunburst sign


S Sheetal1, Ancil George Thomas2,  
1 Department of Neurology, Pushpagiri Institute of Medical Sciences and Research Centre, Thiruvalla, Kerala, India
2 Department of Neurology, Muthoot Hospital, Kozhencherry, Kerala, India

Correspondence Address:
Dr. S Sheetal
16 FG, The Edge, Skyline Apartments, Thirumoolapuram, Thiruvalla - 689 115, Kerala
India




How to cite this article:
Sheetal S, Thomas AG. The sunburst sign.Arch Med Health Sci 2020;8:316-317


How to cite this URL:
Sheetal S, Thomas AG. The sunburst sign. Arch Med Health Sci [serial online] 2020 [cited 2021 Feb 26 ];8:316-317
Available from: https://www.amhsjournal.org/text.asp?2020/8/2/316/304721


Full Text



Sir,

A 74-year-old male with a history of Type 2 diabetes mellitus and systemic hypertension presented with the complaints of insidious-onset and gradually progressive memory impairment and slowness in walking for the past 3 months. He was noted to drag his left leg on walking. He denied any history of headache, vomiting, or seizures. On examination, he had evidence of frontal and temporal lobe dysfunction and spasticity of the left lower limb with left extensor plantar. Magnetic resonance imaging (MRI) of the brain showed a well-defined, extra-axial, dural-based, smoothly marginated, bi-lobed lesion, in the midline and parasagittal parieto-occipital region, straddling and mildly displacing the posterior falx toward the left side with invasion into the adjacent superior sagittal sinus [Figure 1]. Both the parasagittal components were seen displacing the adjacent brain parenchyma with an intervening cerebrospinal fluid (CSF) cleft [Figure 1d]. The lesion was noted to exhibit homogeneous T1-weighted hypointense, T2/T2 fluid-attenuated inversion recovery hyperintense signal, with near-homogeneous postcontrast enhancement. Adjacent bilateral parieto-occipital dura and the posterior falx showed smooth thickening and increased enhancement, suggestive of dural tail sign [Figure 1d]. Radial sunburst pattern was noted in the lesion on T2-weighted and postcontrast images, more prominent in the right-sided component [Figure 1]. All these features were suggestive of meningioma. He was referred for surgery.{Figure 1}

Meningiomas are the most common dural tumors.[1] On computed tomography imaging, majority of meningiomas are hyperdense to the cortex and may show intratumoral calcification. Meningiomas are usually isointense to the cortex on all MRI sequences, however T2 hyperintensity may be seen in 50% of the cases, due to hypervascularity.[1] They do not usually demonstrate diffusion restriction, and more than 50% cause perilesional vasogenic edema.[1] A CSF cleft may be seen between the tumor body and the brain parenchyma.[2] Most meningiomas demonstrate strong enhancement on postcontrast imaging and a dural tail sign is seen in up to 72% of cases, due to reactive thickening and enhancement of the dura.[3] Dural metastatic lesions are typically hyperintense on T2 sequence, whereas lymphoma is typically isointense to hypointense in T2-weighted sequence. Other meningioma mimics include solitary fibrous tumors (SFTs) and melanoma, nonneoplastic processes such as tuberculosis and sarcoidosis, and autoimmune diseases such as immunoglobulin G4-related disease.[1] The sunburst sign or spoke wheel appearance is a radiological sign seen in meningiomas.[1],[4] The sunburst sign refers to the characteristic vascular supply seen in some meningiomas, when seen tangential to the dural attachment. Dural branches of the external carotid artery, internal carotid artery, and vertebral artery may supply the tumor, and pial arteries may also become parasitized by the tumor. The feeder arterial branches diverge radially into the lesion, distributed like sunrays, giving the appearance of a sunburst on T2-weighted or postcontrast images, or during angiography.[5] Low-grade SFTs, which mimic meningioma, may have “fluffy” contrast enhancement rather than a sunburst sign.[1] Flow voids, described as absence of signal on MR images, caused by blood or cerebral spinal fluid flow, are seen in meningiomas and SFTs. Intracranial SFTs on MR images are reported to show a serpentine flow void, however a sunburst flow void is reported to be typical of meningioma.[4] Meningeal hemangiopericytomas are aggressive versions of SFTs of the dura, and they also show multiple flow voids on MRI and a fluffy staining on angiography. On magnetic resonance spectroscopy, meningiomas exhibit high choline: creatinine ratio and low N-Acetyl Aspartate (NAA) peak. Alanine peak, if present, is characteristic. Meningiomas have many characteristic imaging features, one of which is the sunburst sign, which helps in differentiating from other dural-based pathologies.

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References

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3Tokumaru A, O'uchi T, Eguchi T, Kawamoto S, Kokubo T, Suzuki M, et al. Prominent meningeal enhancement adjacent to meningioma on Gd-DTPA-enhanced MR images: Histopathologic correlation. Radiology 1990;175:431-3.
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