CASE 13166 Published on 28.08.2016

An interesting case of tumefactive demyelination

Section

Neuroradiology

Case Type

Clinical Cases

Authors

Kalia Shekhar, Cecil M Deepti, Chaturvedi Arti, Shekhar Abhishek, Kapoor Dinesh

Department of Radiology,
Fortis Hospital,
B -22, Sector - 62,
Pin- 201301, Noida;
Email:shekhar6903@gmail.com

Patient

44 years, male

Categories

Area of Interest Neuroradiology brain ; Imaging Technique PET-CT, MR, MR-Diffusion/Perfusion, MR-Functional imaging, MR-Spectroscopy, Experimental

Procedure Image compression, Imaging sequences, Diagnostic procedure ; Special Focus Inflammation, Tissue characterisation ;

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Clinical History

A 44-year-old gentleman, a known case of pulmonary sarcoidosis since 10 years, came to the ER department following an episode of seizure along with sudden onset weakness on the right side of the face and right lower limb. Clinically, vasculitis-induced stroke or a glioma were suspected.

Imaging Findings

CECT showed an ill-defined hypoattenuating lesion in left corona radiata and centrum semiovale (Fig. 1). This was hyperintense on T2/FLAIR and hypointense on T1WI (Fig. 2); showed peripheral DWI hyperintensity and signal drop on ADC (Fig. 3) with subtle open ring type of peripheral enhancement (Fig. 4). Spectroscopy showed elevated choline, creatine, reduced NAA and a lactate doublet peak on long TE; elevation of glutamate-glutamine peaks on short TE (Fig. 5). Arterial Spin Labelling maps displayed peripheral arc of hyperperfusion (Fig. 6).
Oligoclonal bands were not present on CSF examination and FDG PET-CT revealed reduced uptake in the lesion (Fig. 7). Since the diagnosis was indeterminate, a surgical biopsy was done and histopathology showed tumefactive demyelination with loss of myelin, preserved axons, presence of macrophages, lymphocytosis and astrocytosis (Fig. 8). Post-treatment MRI after 6 months demonstrated resolution of both diffusion restriction and enhancement. (Fig. 9)

Discussion

Tumefactive demyelinating lesion (TDL), is a rare type of unifocal aggressive demyelination, usually larger than 2cm, commonly located in the frontal and parietal lobes and less commonly in the brain stem, temporal lobes, cerebellum and deep grey matter [1, 2]. It can mimic many malignant (lymphoma, glioma) and benign (abscess, acute disseminated encephalomyelitis, granulomas or stroke) lesions [2].

In our case, the left frontoparietal lesion was hypodense on CECT and the diagnostic challenge was to differentiate it from a tumour or sarcoid-induced vasculitic infarct. The lesion displayed ill-defined T2/FLAIR white matter hyperintensity and T1WI hypointensity with no definite mass effect. It showed subtle open ring type of enhancement with discontinuity towards cortex and discontinuous peripheral restriction of diffusion which is common in TDL [3, 4]. Additional documented imaging features of TDL are necrosis, cystic changes, mass effect and variable amount of grey matter involvement [3] . They can also show uniform enhancement, ring-like or central venular, variable/complex enhancement [1, 2].

Studies have shown that mean relative cerebral blood volume and FDG uptakes in TDL is less than in tumours [5, 6]. Variable FDG uptake can be seen depending on the activity of lesion [5]. In our case, FDG uptake was low. The arterial spin labelling map showed hyperperfusion at the inner margins of the lesion, suggesting active disease.

Long TE MR spectroscopy showed increased choline; reduced NAA; elevated lactate peak. Short TE spectroscopy showed elevated glutamine-glutamate peak which is specific to TDL [7, 8]. There may be no significant differences in Cho/Cr ratios in TDL and gliomas. However, the mean NAA/Cr ratio may show marked reduction in central parts of gliomas compared to TDL and this can be used as a differentiating feature [7, 8]. In our case NAA/Cr ratio was mildly reduced (0.86). In the absence of oligoclonal bands in CSF and larger lesional size, a definite diagnosis could not be made and diagnosis of TDL was confirmed on surgical biopsy and systemic steroids were started [2]. Corticosteroid therapy usually improves the clinical symptoms and may reduce the size of the lesion as was in our case. TDL may progress to multiple sclerosis, remain isolated or show recurrence. [1, 2]

It is crucial to differentiate TDL from its mimics and avoid an unnecessary brain biopsy. In indeterminate cases, biopsy should preferably be targeted from the wall of the lesion, contrary to tumours where the central zone of the lesion is preferred [9, 10].

Differential Diagnosis List

Tumefactive demyelination.

Glioma

Stroke

ADEM

Lymphoma

Metastasis

Abscess

Neurosarcoidosis

Final Diagnosis

Tumefactive demyelination.

References

[1] Siri A, Carra-Dalliere C, Ayrignac X, Pelletier J, Audoin B, Pittion-Vouyovitch S, Debouverie M, Lionnet C, Viala F, Sablot D, Brassat D, Ouallet JC, Ruet A, Brochet B, Taillandier L, Bauchet L, Derache N, Defer G, Cabre P, de Seze J, Lebrun Frenay C, Co (2015) Isolated tumefactive demyelinating lesions: diagnosis and long-term evolution of 16 patients in a multicentric study. Journal of Neurology Volume 262, Issue 7, pp 1637–1645 (PMID: 25929666)

[2] Lucchinetti CF, Gavrilova RH, Metz I, Parisi JE, Scheithauer BW, Weigand S, Thomsen K, Mandrekar J, Altintas A, Erickson BJ, König F, Giannini C, Lassmann H, Linbo L, Pittock SJ, Brück W. (2008) Clinical and radiographic spectrum of pathologically confirmed tumefactive multiple sclerosis. Brain - journal of neurology Jul;131(Pt 7):1759-75. doi: 10.1093/brain/awn098. Epub 2008 Jun 5. (PMID: 18535080)

[3] Aria Fallah, Sarfaraz Banglawala, Shanil Ebrahim, John E. Paulseth, and Neilank K. Jha (2010) Tumefactive demyelinating lesions: a diagnostic challenge. Canadian Journal of Surgery Feb; 53(1): 69–70. (PMID: 20100418)

[4] Abou Zeid N, Pirko I, Erickson B, Weigand SD, Thomsen KM, Scheithauer B, Parisi JE, Giannini C, Linbo L, Lucchinetti CF. (2012) Diffusion-weighted imaging characteristics of biopsy-proven demyelinating brain lesions. Neurology 2012 May 22; 78(21): 1655–1662.22;78(21):1655-62. doi: 10.1212/WNL.0b013e3182574f66. Epub 2012 May 9 (PMID: 22573639)

[5] Kimiteru Ito et al (2016) Imaging Spectrum and Pitfalls of 11C-Methionine Positron Emission Tomography in a Series of Patients with Intracranial Lesions. Korean J Radiol 17(3): 424–434. (PMID: 27134530)

[6] Cha S, Pierce S, Knopp EA, Johnson G, Yang C, Ton A, Litt AW, Zagzag D. (2001) Dynamic contrast-enhanced T2*-weighted MR imaging of tumefactive demyelinating lesions. AJNR Am J Neuroradiol Jun-Jul;22(6):1109-16. (PMID: 11415906)

[7] Cianfoni A et al (2007) Metabolite findings in tumefactive demyelinating lesions utilizing short echo time proton magnetic resonance spectroscopy. AJNR Am J Neuroradiol Feb;28(2):272-7. (PMID: 17296993)

[8] Saindanea AM, Cha S, Law M et al (2002) Proton MR Spectroscopy of Tumefactive Demyelinating Lesions. AJNR Am J Neuroradiol. Sep; 23(8):1378-86. AJNR Am J Neuroradiol. 2002 Sep;23(8):1378-86 (PMID: 12223381)

[9] Neelima R, Krishnakumar K, Nair MD, Kesavadas C, Hingwala DR, Radhakrishnan VV, Nair SS. (2012) Tumefactive demyelinating lesions: A Clinicopathological correlative study. Indian J Pathol Microbiol 2012 Oct-Dec;55(4):496-500. doi: 10.4103/0377-4929.107788. (PMID: 23455787)

[10] Kepes JJ (1993) Large focal tumor-like demyelinating lesions of the brain: intermediate entity between multiple sclerosis and acute disseminated encephalomyelitis? A study of 31 patients. Ann Neurol Jan;33(1):18-27. (PMID: 8494332)

Case information

URL:	https://www.eurorad.org/case/13166
DOI:	10.1594/EURORAD/CASE.13166
ISSN:	1563-4086

License

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Figure 1

Axial diffusion-weighted image and ADC map of the brain

Diffusion-weighted image showing altered arc-like hyperintensity at the periphery of the lesion, representing acute aetiology.

The diffusion hyperintensity shows signal drop on ADC maps suggestive of restricted diffusion at the periphery of the lesion (arrows); The central region of the lesion shows normal diffusion.

Figure 2

MRI Brain T2/T1WI and FLAIR sequences

Axial T2WI image showing an ill-defined hyperintensity in left centrum semiovale. No definite mass effect is noted.

Axial T1WI image showing an ill-defined hypointensity in left centrum semiovale. No definite mass effect is noted.

Axial FLAIR image showing an ill-defined hyperintensity in left centrum semiovale.

Coronal T2WI image showing an ill-defined hyperintensity in left centrum semiovale, periventricular and subcortical white matter. No definite mass effect is noted.

Figure 3

Post gadolinium MRI Brain coronal and axial sequences

Post-contrast coronal MRI image showing a faint rim of discontinuous enhancement at the medial aspect of the lesion with open ring towards cortical grey matter.

Post-contrast axial MRI image showing a faint rim of discontinuous enhancement at the medial aspect of the lesion with open ring towards cortical grey matter.

Figure 4

MR spectroscopy brain

MRI spectroscopy indicating the region of interest.

MRI spectroscopy graph at 144 TE showing elevated choline and creatine levels with reduction in NAA and inverted lactate peak.

MRI Spectroscopy graph at 35 TE showing elevation of glutamine /glutamate peak.

Figure 5

CECT Brain

CECT showing an ill-defined hypoattenuating lesion in left centrum semiovale.

Figure 6

Histopathology

Photomicrograph of the biopsied specimen of the lesion showing prominent macrophages and a bizzare gemistocyte (large blue-stained cell) which may lead to incorrect diagnosis of glial neoplasm.

Photomicrograph of the biopsied specimen shows prominent perivascular lymphocyte and histiocytic proliferation.

Photomicrograph of the biopsied specimen after myelin stain showing normal myelinated brain parenchyma on right side(in blue), compared with area of the demyelination(pink on left side).

Figure 7

Follow-up MRI brain after 6 months post treatment

Diffusion-weighted image shows no definite rim of restriction, which was appreciated in the initial scans.

Contrast-enhanced T1WI axial MRI image showing no enhancement. Surgical changes are also seen in left fronto-parietal calvarium (related to previous biopsy).

Axial T2/ FLAIR image shows reduction in the size and extent of the white matter signal alteration.

Figure 8

Arterial spin labelling

T1WI showing hypointense lesion in left centrum semiovale region. (for reference)

A colored arterial spin labelling map demonstrating rim of hyperperfusion giving a characteristic open ring appearance (yellow; ROI-1) in the active zone of demyelination in left centrum semiovale region.

Figure 9

FDG - PET CT Brain