Small Cell Lung Carcinoma Metastasis to Atypical Meningioma: Importance of Perfusion
Magnetic Resonance Imaging Graphics in Differential Diagnosis
Mehmet C¸ agri Danisman1, Mustafa Koplay1, Yahya Paksoy1, Kazım Serhan Keles¸oglu1, Pınar Karabaglı2, Ender Ko¨ktekir3
A 70-year-old man with small cell lung cancer who had a dizziness complaint was admitted to our hospital. We performed brain magnetic resonance imaging (MRI) including susceptibility-weighted imaging, perfusion MRI (pMRI), and spectroscopy to investigate the presence of intracranial metastasis. A dural-based lesion measuring 2.5 cm in diameter was located at the left frontal extraaxial region. The lesion was hyperintense on T2-weighted images, and it had diffuse homogeneous contrast enhancement. There was no calcification observed in the susceptibility-weighted imaging sequence (Figures 1and2).
The lesion resembled meningioma on routine MRI. However, due to the absence of extracellular area contrast leakage that has a T1 effect on perfusion MRI
examination, it was thought that there could be a secondary condition accompa-nying meningioma. Frankly, perfusion graphics did not show typical meningioma perfusion graphics (Figure 3). The histopathology of the lesion was small cell lung carcinoma metastasized into the atypical meningioma.
Metastases of systemic cancers into primary intracranial tumors are rare situ-ations.1 In this case, we aimed to emphasize the importance of pMRI graphics at the differential diagnosis and also present the imaging findings of small cell lung cancer metastasis into an atypical meningioma.
pMRI is an imaging modality in which serial images are obtained after intrave-nous contrast agent administration. The amount of the contrast agent routinely administered to the patient does not change because pMRI sequences are ob-tained before contrast-enhanced standard sequences during the same contrast agent administration. It is a method for imaging the passage of contrast agent through tissue. Different enhancement patterns and different perfusion graphics are formed depending on the vascularity of tumors. There are 3 different types of pMRI methods. These are dynamic sus-ceptibility contrast MRI perfusion, dynamic contrast-enhanced MRI perfu-sion, and arterial spin labeling MRI perfusion. We use dynamic susceptibility contrast perfusion imaging. With this
technique, blood volume andflow in the tissue and contrast material leakage to the extracellular area can be calculated and graphics can be created. The area under the curve represents the blood volume of the area of interest. This gives information about the vascularity of tumors whether there is a high or low vascularity.
Perfusion curves have T1- and T2-dominant contrast leakage curve patterns that show the intensity of contrast leakage in tissue. In a study, it was mentioned that T1-dominant contrast leakage curve shows a smaller amount of contrast leakage and T2-dominant contrast leakage curve shows a higher amount of contrast leakage.2This study shows that T2-dominant contrast leakage and return-to-baseline patterns show high positive predictive value (95%) for high-grade tumors and a T1-dominant contrast leakage pattern is highly specific for low-grade tumors at perfusion graphics. For differential diagnosis of meningi-omas, advanced imaging methods like pMRI and perfusion graphics may have great importance. Meningiomas typically show increased relative cerebral blood volume. pMRI does not cause an increase in the dosage of contrast agent. pMRI takes a relatively short time, it is cost-effective, and it provides useful informa-tion. To be able to determine subtypes of meningiomas and differentiate whether they are malignant or benign may provide a preoperative idea to determine prognosis and surgical procedure.
We described the imaging findings of small cell lung carcinoma metastasis to atypical meningioma and the importance of magnetic resonance imaging perfusion graphics at the differential diagnosis. To be able to determine subtypes of meningiomas and differentiate whether they are malignant or benign may provide a preoperative idea to determine prognosis and surgical procedure.
Key words
-Lung carcinoma
-Meningioma
-Magnetic resonance imaging
-Perfusion
Abbreviations and Acronyms
MRI: Magnetic resonance imaging
pMRI: Perfusion MRI
SWI: Susceptibility-weighted imaging
From the Departments of1
Radiology,2
Pathology, and
3
Neurosurgery, Medical of Faculty, Selcuk University, Konya, Turkey
To whom correspondence should be addressed: Mustafa Koplay, M.D.
[E-mail:koplaymustafa@hotmail.com] Citation: World Neurosurg. (2019) 124:410-413.
https://doi.org/10.1016/j.wneu.2019.01.084
Journal homepage: www.journals.elsevier.com/world-neurosurgery
Available online:www.sciencedirect.com
1878-8750/$ - see front matterª 2019 Elsevier Inc. All rights reserved.
410 www.SCIENCEDIRECT.com WORLD NEUROSURGERY,https://doi.org/10.1016/j.wneu.2019.01.084
REFERENCES
1. Nagar VA, Ye JR, Ng WH, et al. Diffusion-weighted MR imaging: diagnosing atypical or malignant meningiomas and detecting tumor dedifferentia-tion. AJNR Am J Neuroradiol. 2008;29:1147-1152.
2. Ho CY, Cardinal J, Kamer AP, Lin C, Kralik SF. Contrast leakage patterns from dynamic
suscepti-bility contrast perfusion MRI in the grading of primary pediatric brain tumors. AJNR Am J Neuro-radiol. 2016;37:544-551.
Conflict of interest statement: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Received 21 September 2018; accepted 8 January 2019
Citation: World Neurosurg. (2019) 124:410-413.
https://doi.org/10.1016/j.wneu.2019.01.084
Journal homepage: www.journals.elsevier.com/world-neurosurgery
Available online:www.sciencedirect.com
1878-8750/$ - see front matterª 2019 Elsevier Inc. All rights reserved.
Figure 1. Axial T1-weighted (A) and axial T2-weighted (B) images show an extraaxial mass and parenchymal edema (arrows). Diffusion-weighted imaging (C) and
apparent diffusion coefficient map (D) show the diffusion restriction in the lesion (arrows).
WORLD NEUROSURGERY124: 410-413, APRIL2019 www.journals.elsevier.com/world-neurosurgery 411
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Figure 2. Contrast-enhanced axial T1-weighted image (A) shows diffuse homogeneous contrast
enhancement in the lesion. SWI sequence (B) shows
no calcification in the lesion. The spectroscopy images (C and D) show elevated choline values and Cho/Cr ratio.
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CLINICALIMAGES
Figure 3. Perfusion graphics did not show T1-dominant contrast leakage pattern on perfusion magnetic resonance imaging examination, which is typically seen
on benign brain tumors. There is a return-to-baseline pattern on perfusion graphic (AeD).
WORLD NEUROSURGERY124: 410-413, APRIL2019 www.journals.elsevier.com/world-neurosurgery 413
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