Tumefactive multiple sclerosis requiring emergent biopsy and histological investigation to confirm the diagnosis: a case report

Abstract

Introduction: Tumefactive multiple sclerosis is a demyelinating disease that demonstrates tumor-like features on magnetic resonance imaging. Although diagnostic challenges without biopsy have been tried by employing radiological studies and cerebrospinal fluid examinations, histological investigation is still necessary for certain diagnosis in some complicated cases.

Case presentation: A 37-year-old Asian man complaining of mild left leg motor weakness visited our clinic. Magnetic resonance imaging demonstrated high-signal lesions in bilateral occipital forceps majors, the left caudate head, and the left semicentral ovale on fluid-attenuated inversion recovery and T2-weighted imaging, and these lesions were enhanced by gadolinium-dimeglumin. Tumefactive multiple sclerosis was suspected because the enhancement indistinctly extended along the corpus callosum on magnetic resonance imaging and scintigraphy showed a low malignancy of the lesions. But oligoclonal bands were not detected in cerebrospinal fluid. In a few days, his symptoms fulminantly deteriorated with mental confusion and left hemiparesis, and steroid pulse therapy was performed. In spite of the treatment, follow-up magnetic resonance imaging showed enlargement of the lesions. Therefore, emergent biopsy was performed and finally led to the diagnosis of demyelinating disease. The enhanced lesion on magnetic resonance imaging disappeared after one month of prednisolone treatment, but mild disorientation and left hemiparesis remained as sequelae.

Conclusions: Fulminant aggravation of the disease can cause irreversible neurological deficits. Thus, an early decision to perform a biopsy is necessary for exact diagnosis and appropriate treatment if radiological studies and cerebrospinal fluid examinations cannot rule out the possibility of brain tumors.

Figure 1

Pre-operative magnetic resonance imaging. High-intensity areas in bilateral occipital forceps majors, the left caudate head, and the left semicentral ovale are shown in both fluid-attenuated inversion recovery (FLAIR) and T2-weighted (T2W) imaging. These lesions are enhanced indistinctly by gadolinium-dimeglumin (Gd).

Figure 2

Uptake of thallium in the lesions on ²⁰¹Tl scintigraphy. Definite uptake of thallium is identified in the lesions. However, the retention index (ratio of thallium uptake between late and early phases) is 0.88, suggesting a low possibility of malignancy.

Figure 3

Magnetic resonance imaging after steroid pulse therapy. High-intensity areas in the left caudate head, bilateral semicentral ovales, and bilateral occipital forceps majors are clearly enlarged on FLAIR and T2W imaging. Gd-enhanced lesions in the occipital forceps majors are clearly expanded.

Figure 4

Definite diagnosis of tMS by histological investigations. Histology shows proliferation of lymphocytes (arrowheads) without atypical features by hematoxylin-eosin (HE) staining (a). Kluver-Barrera staining demonstrates sporadic defects of myelin (arrows), indicating demyelinations (b). Perivascular lymphocyte proliferation is recognized by HE staining (c). These lymphocytes are composed mainly of CD3-positive T-cell lymphocytes (d), and a mixture of CD4-positive (e) and CD8-positive (f) T-cell lymphocytes rules out monoclonal increase of the lymphocytes. The appearance of macrophages (CD68) in the lesion strongly suggests inflammatory disease (g) rather than malignant lymphoma. CD: cluster of differentiation.

Figure 5

MRI after one month of steroid therapy. High-intensity areas in (FLAIR) and T2W imaging considerably shrink and Gd-enhanced lesions completely disappear after one month of steroid treatment. Arrows show the point of biopsy.