Case Report
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Nov 16, 2015; 3(11): 956-964
Published online Nov 16, 2015. doi: 10.12998/wjcc.v3.i11.956
Differential diagnosis of a vanishing brain space occupying lesion in a child
Sherifa A Hamed, Mohamad A Mekkawy, Hosam Abozaid
Sherifa A Hamed, Department of Neurology and Psychiatry, Assiut University Hospital, Assiut 71516, Egypt
Mohamad A Mekkawy, Department of Oncology, Assiut University Hospital, Assiut 71516, Egypt
Hosam Abozaid, Department of Radiology, Assiut University Hospital, Assiut 71516, Egypt
Author contributions: All the authors equally contributed to this work.
Institutional review board statement: This study was reviewed by and received exemption from the Assiut University Hospital Institutional Review Board.
Informed consent statement: The study participant provided written informed consent for inclusion in this case report.
Conflict-of-interest statement: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Dr. Sherifa A Hamed, MD, Consultant Neurologist, Professor, Department of Neurology and Psychiatry, Assiut University Hospital, Floor # 7, Room # 4, Assiut 71516, Egypt.
Telephone: +2-88-2371820 Fax: +2-88-2333327
Received: April 15, 2015
Peer-review started: April 18, 2015
First decision: May 13, 2015
Revised: June 30, 2015
Accepted: August 4, 2015
Article in press: August 7, 2015
Published online: November 16, 2015

We describe clinical, diagnostic features and follow up of a patient with a vanishing brain lesion. A 14-year-old child admitted to the department of Neurology at September 2009 with a history of subacute onset of fever, anorexia, vomiting, blurring of vision and right hemiparesis since one month. Magnetic resonance imaging (MRI) of the brain revealed presence of intra-axial large mass (25 mm × 19 mm) in the left temporal lobe and the brainstem which showed hypointense signal in T1W and hyperintense signals in T2W and fluid attenuated inversion recovery (FLAIR) images and homogenously enhanced with gadolinium (Gd). It was surrounded by vasogenic edema with mass effect. Intravenous antibiotics, mannitol (2 g/12 h per 2 d) and dexamethasone (8 mg/12 h) were given to relief manifestations of increased intracranial pressure. Whole craniospinal radiotherapy (brain = 4000 CGy/20 settings per 4 wk; Spinal = 2600/13 settings per 3 wk) was given based on the high suspicion of neoplastic lesion (lymphoma or glioma). Marked clinical improvement (up to complete recovery) occurred within 15 d. Tapering of the steroid dose was done over the next 4 mo. Follow up with MRI after 3 mo showed small lesion in the left antero-medial temporal region with hypointense signal in T1W and hyperintense signals in T2W and FLAIR images but did not enhance with Gd. At August 2012, the patient developed recurrent generalized epilepsy. His electroencephalography showed the presence of left temporal focus of epileptic activity. MRI showed the same lesion as described in the follow up. The diffusion weighted images were normal. The seizures frequency was decreased with carbamazepine therapy (300 mg/12 h). At October 2014, single voxel proton (1H) MR spectroscopy (MRS) showed reduced N-acetyl-aspartate (NAA)/creatine (Cr), choline (Cho)/Cr, NAA/Cho ratios consistent with absence of a neoplasm and highly suggested presence of gliosis. A solitary brain mass in a child poses a considerable diagnostic difficulty. MRS provided valuable diagnostic differentiation between tumor and pseudotumor lesions.

Keywords: Vanishing brain mass, Gliosis, Unconfirmed diagnosis, Lymphoma, Granuloma

Core tip: A vanishing brain space occupying lesion is defined as reduction or disappearance of a brain lesion spontaneously or after steroid treatment to ≤ 70% of its size before establishing its definitive diagnosis. A vanishing solitary neoplastic/non-neoplastic (pseudotumor) (e.g., infection/abscess, granuloma, radiation necrosis, multiple sclerosis) brain mass in a child poses a considerable diagnostic difficulty particularly deeply seated lesions in which tissue diagnosis is difficult to be done. In clinical practice, neuroimaging has to be done every 6-12 mo for at least 3-5 years to follow up after complete remission of the patient. Magnetic resonance spectroscopy (MRS) has been proved to be valuable for diagnostic differentiation between tumor and pseudotumor lesions. MRS provides information related to the metabolic activity in the culprit lesion (e.g., neoplastic processes, demyelination, cell necrosis or gliotic changes).