Indian Journal of Pathology and Microbiology

LETTER TO EDITOR
Year
: 2018  |  Volume : 61  |  Issue : 4  |  Page : 638--640

Tumefactive demyelination versus tumor; A diagnostic dilemma: Role of electron microscopy


Paresh Doshi1, Raghvendra Ramdasi1, Smita Thorve1, Shaila Khubchandani2,  
1 Department of Neurosurgery, Jaslok Hospital and Research Centre, Mumbai, Maharashtra, India
2 Department of Pathology, Jaslok Hospital and Research Centre, Mumbai, Maharashtra, India

Correspondence Address:
Raghvendra Ramdasi
Department of Neurosurgery, Jaslok Hospital and Research Centre, 15, Dr. Deshmukh Marg, Pedder Road, Mumbai - 400 026, Maharashtra
India




How to cite this article:
Doshi P, Ramdasi R, Thorve S, Khubchandani S. Tumefactive demyelination versus tumor; A diagnostic dilemma: Role of electron microscopy.Indian J Pathol Microbiol 2018;61:638-640


How to cite this URL:
Doshi P, Ramdasi R, Thorve S, Khubchandani S. Tumefactive demyelination versus tumor; A diagnostic dilemma: Role of electron microscopy. Indian J Pathol Microbiol [serial online] 2018 [cited 2019 Jul 21 ];61:638-640
Available from: http://www.ijpmonline.org/text.asp?2018/61/4/638/243002


Full Text



Editor,

A 46-year-old male presented with headache for 3 months and difficulty in calculation for 15 days. On examination, the patient had acalculia and left agraphesthesia. His magnetic resonance imaging (MRI) revealed a 5.8 cm × 1.6 cm lesion involving body and splenium of corpus callosum on the left side. It was isointense on T1-weighted, heterogeneously hyperintense on T2-weighted, and fluid-attenuated inversion recovery sequences [Figure 1]a, [Figure 1]b, [Figure 1]c. It showed ring enhancement on giving gadolinium [Figure 1]d. It showed restricted diffusion on diffusion-weighted imaging [Figure 1]e. It showed lipid peaks and high choline/creatine ratio on spectroscopy suggestive of neoplastic conditions-like glioma or lymphoma. Stereotactic biopsy of the lesion was performed and sent for histopathological examination.{Figure 1}

The tissue was pink, friable on gross examination. The microscopy showed the vacuolation of cells with interstitial edema [Figure 2]a and [Figure 2]b. Luxol fast blue staining did not reveal demyelination [Figure 2]c and [Figure 2]d. Due to the inconclusive findings, we opted for electron microscopy. It showed prominent degenerative changes of the myelin in the form of vacuolation and granularity with areas of complete demyelinated axons. Few cells engulfing the lipid material resembling histiocytes were seen [Figure 3]a, [Figure 3]b, [Figure 3]c, [Figure 3]d.{Figure 2}{Figure 3}

Based on these findings, diagnosis of tumefactive demyelination was established, and the patient was started on steroids. The patient dramatically improved in his symptoms at 15 months follow-up.

Tumefactive demyelinating lesions (TDL) are solitary demyelinating lesions with a dimension of >2 cm.[1] These are types of demyelinating lesions where they form mass resembling a tumor (glioma and lymphoma) hence named so.[2] After the first description in 1993, very few cases of TDL have been reported.[3] Symptomatology, imaging, and even histopathology are imperfect tools for accurate diagnosis. This is the first report where electron microscopy was effectively used for the conclusive diagnosis when other modalities failed.

The clinical presentations include acute onset focal weakness, seizure episodes, and intractable headaches.[1],[3] Gerstmann syndrome comprising of dysgraphia, dyscalculia, finger agnosia, and left-right disorientation is only once reported in case of tumefactive demyelination. In our case, the patient had partial Gerstmann syndrome.[4]

On MRI, TDLs resemble high-grade glial neoplasms in having ill-defined borders, mass effect, perilesional edema, central necrosis, and contrast enhancement.[5] There are few differentiating points. It has a size of >2 cm, but with minimal mass effect or edema. The enhancement is usually ring like and is incomplete (open) on the cortical side due to a paucity of inflammation on that side. It may have large central dilated vein on T2 echoplanar images and decreased perfusion on MR perfusion scan. The average relative cerebral blood volume (rCBV) is usually <1 in TDL, >2 for lymphomas and >6 for gliomas.[1] Saindane et al. found on MR spectroscopy NAA/Cr ratio is markedly decreased in the center of the glioma as compared to that of TDL with rest biochemical alterations being nonspecific. Lactate and glutamate/are preferentially increased in TDL.[5] However, no single value is diagnostic. In our case, the only rCBV was the only positive parameter.

Stereotactic biopsy targeted at the active wall of the lesion is effective for tissue diagnosis. The characteristic histopathological features include reactive gliosis, foamy macrophages, and lymphocytic infiltrate which are nonspecific.[3] Demyelination demonstrated by Luxol fast blue may not be seen in every case as in ours. Ours is the first report where TDL was conclusively diagnosed on electron microscopy. In electron microscopy, degenerative changes of the myelin are seen well.

The most patients of TDL have a single attack and do not progress to multiple sclerosis and respond well to steroids.[3],[5] Hence, in case of clinically and radiologically suspicious but histopathologically equivocal lesions electron microscopy should be used generously to avoid inadvertent radical surgery and radiotherapy in this nonneoplastic conditions.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Acknowledgment

The author would like to thank Prof. S. M. Katrak.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Rajasekharan C, Anto V, Unnikrishnan R. Tumefactive demyelination-to cracks the nut without cracking the pot. BMJ Case Rep 2012;2012. pii: bcr0120125504.
2Law M, Meltzer DE, Cha S. Spectroscopic magnetic resonance imaging of a tumefactive demyelinating lesion. Neuroradiology 2002;44:986-9.
3Neelima R, Krishnakumar K, Nair MD, Kesavadas C, Hingwala DR, Radhakrishnan VV, et al. Tumefactive demyelinating lesions: A clinicopathological correlative study. Indian J Pathol Microbiol 2012;55:496-500.
4Gnanapavan S, Jaunmuktane Z, Baruteau KP, Gnanasambandam S, Schmierer K. A rare presentation of atypical demyelination: Tumefactive multiple sclerosis causing Gerstmann's syndrome. BMC Neurol 2014;14:68.
5Saindane AM, Cha S, Law M, Xue X, Knopp EA, Zagzag D, et al. Proton MR spectroscopy of tumefactive demyelinating lesions. AJNR Am J Neuroradiol 2002;23:1378-86.