A challenging diagnosis of late-onset tumefactive multiple sclerosis associated to cervicodorsal syringomyelia: doubtful CT, MRI, and bioptic findings: Case report and literature review

Abstract

Background: Tumefactive multiple sclerosis (MS) is an unusual variant of demyelinating disease characterized by lesions with pseudotumoral appearance on radiological imaging mimicking other space-occupying lesions, such as neoplasms, infections, and infarction. Especially when the patient's medical history is incompatible with MS, the differential diagnosis between these lesions constitutes a diagnostic challenge often requiring histological investigation. An older age at onset makes distinguishing tumefactive demyelinating lesion (TDL) from tumors even more challenging.

Methods: We report a case of brain TDL as the initial manifestation of late-onset MS associated with cervico-dorsal syringomyelia. A 66-year-old Caucasian woman with a 15-day history headache was referred to our hospital because of the acute onset of paraphasia. She suffered from noncommunicating syringomyelia associated to basilar impression and she reported a 10-year history of burning dysesthesia of the left side of the chest extended to the internipple line level.

Results: Computed tomography (CT) and magnetic resonance imaging (MRI) examinations revealed a left frontal lesion with features suspicious for a tumor. Given the degree of overlap with other pathologic processes, CT and MRI findings failed to provide an unambiguous diagnosis; furthermore, because of the negative cerebrospinal fluid analysis for oligoclonal bands, the absence of other lesions, and the heightened suspicion of neoplasia, the clinicians opted to perform a stereotactic biopsy. Brain specimen analysis did not exclude the possibility of perilesional reactive gliosis and the patient, receiving anitiedemigen therapy, was monthly followed up. In the meanwhile, the second histological opinion of the brain specimen described the absence of pleomorphic glial cells indicating a tumor. These findings were interpreted as destructive inflammatory demyelinating disease and according to the evolution of MRI lesion burden, MS was diagnosed.

Conclusion: TDL still remains a problematic entity clinically, radiologically, and sometimes even pathologically. A staged follow-up is necessary, and in our case, it revealed to be the most important attitude to define the nature of the lesion, confirming the classic MS diagnostic criteria of disseminate lesions in time and space. We discuss our findings according to the recent literature.

Figure 1

(A) Unenhanced CT axial image: hypodense tumefactive lesion in the left frontal lobe with mass effect. (B) Coronal T2-w and (C) axial FLAIR MRI images: the hyperintense lesion has an incomplete peripheral hypointense rim. (D) ADC map: peripheral areas of diffusion restriction appearing hypointese. (E) Postcontrast axial T1-w MRI image: mild peripheral enhancement with nodular foci directed toward the basal ganglia. (F) T2-w sagittal MRI image of the spinal cord: the tip of the odontoid process projects above the foramen magnum and is associated to a syrinx extending from C2 to T1 level. ADC = apparent diffusion coefficient, CT = computed tomography, FLAIR = fluid attenuation inversion recovery, MRI = magnetic resonance imaging.

Figure 2

(A) FLAIR localizing image for proton MR spectroscopy: shrinking of the lesion which shows inner postbioptic air bubble and reduced compression on the left ventricle. (B) Proton MR spectrum of the lesion: elevated Cho value, decreased NAA value, evidence of lip-lac peak caused by the necrosis component, and the absence of -Glx peaks (arrow). (C) Postcontrast axial T1-w MRI image: the lesion is not enhanced. FLAIR = fluid attenuation inversion recovery, MRI = magnetic resonance imaging, NAA = N-acetylaspartate.

Figure 3

Axial FLAIR (A) and postcontrast T1-w (B) MRI images: new enhancing lesion in the right temporal lobe. Axial (C) and coronal (D) FLAIR MRI images: multiple small lesion with MS plaque appearance. FLAIR = fluid attenuation inversion recovery, MRI = magnetic resonance imaging.

Figure 4

Hematoxylin and eosin (A) and Luxol Fast Blue-Periodic Acid Schiff (B) stains: hypercellular lesion with infiltrating macrophages and reactive astrocytes with swollen cell bodies; the tissue structure is loosened.