CASE 13166 Published on 28.08.2016

An interesting case of tumefactive demyelination



Case Type

Clinical Cases


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

Department of Radiology,
Fortis Hospital,
B -22, Sector - 62,
Pin- 201301, Noida;

44 years, male

Area of Interest Neuroradiology brain ; Imaging Technique PET-CT, MR, MR-Diffusion/Perfusion, MR-Functional imaging, MR-Spectroscopy, Experimental
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)
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.
Final Diagnosis
Tumefactive demyelination.
Case information
DOI: 10.1594/EURORAD/CASE.13166
ISSN: 1563-4086