Tumefactive demyelinating lesions: a clinicopathological correlative study

Prognostic factors of tumefactive demyelinating lesions and differential features for multiple sclerosis in etiology

BACKGROUND

Many different pathologies may underlie tumefactive demyelinating lesions. Identifying clinical and radiologic distinguishing features before pathologic examination is essential for diagnosis and treatment. In this study, we aimed to determine the clinical and radiologic features affecting the etiology and disease course of patients with tumefactive lesions (TDL).

MATERIALS AND METHODS

We included 35 clinicoradiologically or histologically diagnosed TDL patients in our center over 11 years. Patient records were retrospectively evaluated and recorded. Clinical features, cerebral neuroimaging, and histologic biopsy preparations, if any, were assessed by three independent neurologists, two neuroradiologists, and two pathologists at admission and follow-up, respectively.

RESULTS

The mean age of patients with TDL was 40.02±14.40 years. Symptom onset was 15 (1-365) days. The most common complaints at initial presentation were hemiparesis or hemiplegia, sensory complaints, and cognitive impairment (aphasia or apraxia). The lesions were most commonly localized in the frontal lobe (42.9 %). Mass effect was 17.1 %, edema 60 %, diffusion restriction 62.1 %, and contrast enhancement 71.9 % (mostly ring-shaped (68.8 %)) on MR images. Acute onset and OCB type-2 positivity were associated with MS diagnosis. On the other hand, CSF protein levels above 45 mg/dL were found to be related to non-MS etiologies. Only the predominance of aphasia or apraxia at onset was a risk factor for early high disability (EDSS>4; 3rd month). Subacute-chronic onset, being older than 40 years, or having brainstem symptoms at onset were independent risk factors for late high disability (2nd year).

CONCLUSION

Acute onset or OCB type 2 positivity is a clue for early diagnosis of MS, while elevated CSF protein is a clue for demyelinating diseases other than MS. Presentation with cognitive dysfunction at onset is an independent risk factor for early disability, while age above 40 years, subacute-chronic presentation and brainstem findings at presentation are independent risk factors for late disability.

T2-fluid attenuated inversion recovery mismatch in tumefactive multiple sclerosis

The T2-fluid attenuated inversion recovery (FLAIR) mismatch sign has been suggested as an imaging marker of isocitrate dehydrogenase-mutant 1p/19q non-codeleted gliomas with 100% specificity. Tumefactive demyelination is a common mimic of neoplasm that has led to unnecessary biopsies and even resections. We report a case of tumefactive multiple sclerosis in a 46-year-old male without prior symptomatic demyelinating episodes that demonstrates the T2-FLAIR mismatch sign. Our findings suggest the T2-FLAIR mismatch sign should not be used as a differential feature between glioma and tumefactive demyelination. Because typical isocitrate dehydrogenase-mutant 1p/19q non-codeleted gliomas typically do not demonstrate significant enhancement, such diagnosis should be reserved when post-contrast images are unavailable.

Tumefactive Demyelination: A Common Radiological Masquerader of Malignancy and the Expeditious Diagnostic Applicability of Crush Smear Cytology

Tumefactive demyelinations (TDs) are demyelinating central nervous system lesions that masquerade as neoplastic lesions on radiological images. Brain biopsy is often required for confirmatory diagnosis. Since crush cytology has become a routine practice, a thorough knowledge of the cytomorphologic features of TD is required to prevent misdiagnosis. In this report, we describe the cytomorphological and histomorphological features of a case of TD.

Tumefactive Demyelinating Lesions in Children: A Rare Case of Conus Medullaris Involvement and Systematic Review of the Literature

Tumefactive demyelinating lesions are an uncommon manifestation of demyelinating disease that mimic primary central nervous system neoplasms and can pose a diagnostic challenge in patients without a pre-existing diagnosis of multiple sclerosis. Although a biopsy may be required to distinguish TDL from neoplasms or infection, certain ancillary and radiographic findings may preclude the need for invasive diagnostic procedures. We describe the case of a 15-year-old boy with a tumefactive demyelinating lesion involving the conus medullaris. An exhaustive systematic literature search of pediatric cases of TDL yielded an additional 78 cases. This review summarizes the current knowledge and recommendations for the diagnosis and management of this condition, highlighting the clinical, demographic, and radiologic features of 79 reported cases, including our own. Furthermore, it underscores areas of the literature where evidence is still lacking. Further research is needed to optimize clinical detection and medical management of this condition.

Tumefactive Demyelination versus Primary Central Nervous System Lymphoma on 18F-Fluorodeoxyglucose Positron Emission Tomography Magnetic Resonance Imaging: A Twist in the Tale

Demyelinating lesions of the central nervous system (CNS) are classically known to be hypometabolic on ¹⁸F-Flurodeoxyglucose Positron Emission Tomography (¹⁸F-FDG PET). However, demyelinating lesions may show increased tracer uptake on ¹⁸F-FDG PET and can radiologically mimic neoplasm. Delayed tracer uptake on FDG PET is one of the diagnostic hallmarks of primary CNS lymphoma (PCNSL). Here, we present two cases in which the brain lesions showed increased FDG uptake on delayed integrated PET Magnetic Resonance Imaging (MRI), which were pathologically proven as CNS demyelination. Such demyelinating lesions may also act as "sentinel lesions" and potential harbinger of PCNSL on follow-up.

Combining Diffusion Tensor Metrics and DSC Perfusion Imaging: Can It Improve the Diagnostic Accuracy in Differentiating Tumefactive Demyelination from High-Grade Glioma?

BACKGROUND AND PURPOSE

Tumefactive demyelinating lesions with atypical features can mimic high-grade gliomas on conventional imaging sequences. The aim of this study was to assess the role of conventional imaging, DTI metrics (p:q tensor decomposition), and DSC perfusion in differentiating tumefactive demyelinating lesions and high-grade gliomas.

MATERIALS AND METHODS

Fourteen patients with tumefactive demyelinating lesions and 21 patients with high-grade gliomas underwent brain MR imaging with conventional, DTI, and DSC perfusion imaging. Imaging sequences were assessed for differentiation of the lesions. DTI metrics in the enhancing areas and perilesional hyperintensity were obtained by ROI analysis, and the relative CBV values in enhancing areas were calculated on DSC perfusion imaging.

RESULTS

Conventional imaging sequences had a sensitivity of 80.9% and specificity of 57.1% in differentiating high-grade gliomas (P = .049) from tumefactive demyelinating lesions. DTI metrics (p:q tensor decomposition) and DSC perfusion demonstrated a statistically significant difference in the mean values of ADC, the isotropic component of the diffusion tensor, the anisotropic component of the diffusion tensor, the total magnitude of the diffusion tensor, and rCBV among enhancing portions in tumefactive demyelinating lesions and high-grade gliomas (P ≤ .02), with the highest specificity for ADC, the anisotropic component of the diffusion tensor, and relative CBV (92.9%). Mean fractional anisotropy values showed no significant statistical difference between tumefactive demyelinating lesions and high-grade gliomas. The combination of DTI and DSC parameters improved the diagnostic accuracy (area under the curve = 0.901). Addition of a heterogeneous enhancement pattern to DTI and DSC parameters improved it further (area under the curve = 0.966). The sensitivity increased from 71.4% to 85.7% after the addition of the enhancement pattern.

CONCLUSIONS

DTI and DSC perfusion add profoundly to conventional imaging in differentiating tumefactive demyelinating lesions and high-grade gliomas. The combination of DTI metrics and DSC perfusion markedly improved diagnostic accuracy.

Open-ring enhancement in pseudotumoral multiple sclerosis: important radiological aspect

Introduction. Observation of open-ring enhancement in magnetic resonance imaging (MRI) is considered a specificity marker for diagnosing pseudotumoral multiple sclerosis (MS). This finding is of great value in the differential diagnosis of tumefactive lesions. Case Report. We describe a 55-year-old white woman, with previous history of ovarian cancer and recent history of fatigue and bilateral retroorbital pain. Important bilateral visual impairment evolved over one month. Physical examination detected the presence of right homonymous hemianopia. Cranial MRI showed an expanding lesion with open-ring enhancement. Given the range of diagnostic possibilities, a stereotactic biopsy was performed, and histopathological examination was consistent with an active demyelinating disease. The patient was treated with 1 g of methylprednisolone and symptoms improved following a significant reduction in the lesion. Conclusions. We highlight the MRI results suggestive of pseudotumoral MS, especially open-ring enhancement, which is an important radiologic aspect to diagnosis and can assist in avoiding unnecessary biopsies.